Likelihood-based inference under nonconvex boundary constraints

Likelihood-based inference under nonconvex constraints on model parameters has become increasingly common in biomedical research. In this paper, we establish large-sample properties of the maximum likelihood estimator when the true parameter value lies at the boundary of a nonconvex parameter space. We further derive the asymptotic distribution of the likelihood ratio test statistic under nonconvex constraints on model parameters. A general Monte Carlo procedure for generating the limiting distribution is provided. The theoretical results are demonstrated by five examples in Anderson's stereotype logistic regression model, genetic association studies, gene-environment interaction tests, cost-constrained linear regression and fairness-constrained linear regression.

Evaluation of granular formulated strigolactone analogs for Striga suicidal germination

BACKGROUND

Striga hermonthica, an obligate root parasitic weed, poses a significant threat to cereal production in sub-Saharan Africa. Lowering Striga seed bank in infested soils is a promising strategy to mitigate infestation levels. The dependency of Striga seed germination on strigolactones opens up the possibility of a 'suicidal germination' approach, where synthetic germination stimulants induce lethal germination in the absence of a host. Implementing this approach requires active germination stimulants with a suitable formulation for field application. Here, we describe the development of slow-releasing granular formulation of two potent germination stimulants 'Methyl Phenlactonoate 3' and 'Nijmegen-1' and the assessment of their activity under Laboratory, greenhouse, mini-field, and field conditions.

RESULTS

Under laboratory conditions, the granular formulation of either of the two germination stimulants (1.25 mg per plate, corresponding to 0.09 mg a.i.) induced Striga seed germination at a rate of up to 43%. With 10 mg granular product (0.75 mg a.i.) per pot, we observed 77-83% reduction in Striga emergence under greenhouse pot conditions. Application of the formulated stimulants under artificially or naturally infested fields resulted in approximately 56%, 60%, and 72% reduction in Striga emergence in maize, sorghum, and millet fields in Kenya and Burkina Faso, respectively.

CONCLUSION

Our findings on the newly designed granular formulation of Methyl Phenlactonoate 3 and Nijmegen-1 reveal encouraging prospects for addressing the Striga problem in Africa. These findings underscore several significant advantages of the formulated stimulants, including suitability for the African agricultural context, and, most importantly, their effectiveness in reducing Striga infection. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

[Role of innate lymphoid cells in oral squamous cell carcinoma microenvironment]

Oral squamous cell carcinoma (OSCC) is the most common oral malignancy. It has a high incidence, strong invasion ability, easy metastasis, poor curative effect, and poor prognosis. Innate lymphoid cells (ILCs) are an important part of immune cells located in the mucosal barrier, which play an important role in the occurrence, development and outcome of tumors. ILCs are the key cells for decoding the regulatory mechanism of tumor microenvironment and the signatures for tumor progression. This paper reviewed the latest progress on ILCs, summarized the possible characteristics and functions of ILCs in the microenvironment of OSCC, and explored the relationship between ILCs and the occurrence, development and immunotherapy of OSCC.

[Preliminary outcomes of neoadjuvant chemoimmunotherapy combined with transoral robotic surgery for locally advanced oropharyngeal squamous cell carcinoma]

Objective: To evaluate the efficacy of neoadjuvant chemoimmunotherapy (NACI) combined with transoral robotic surgery (TORS) in the treatment of locally advanced oropharyngeal squamous cell carcinoma (OPSCC). Methods: This was a retrospective study of 15 patients with locally advanced OPSCC who underwent TORS after neoadjuvant therapy (NAT) at the Department of Otolaryngology-Head and Neck Surgery of Sun Yat-sen Memorial Hospital of Sun Yat-sen University from April 2019 to February 2023. There were 12 males and 3 females, aged 31 to 74 years. Twelve cases were tonsil cancer, and 3 cases were tongue base cancer. There were 11 cases in stage Ⅲ and 4 cases in stage Ⅳ. Two patients received neoadjuvant chemotherapy and 13 patients received NACI, with 2 to 3 cycles, and all patients underwent TORS after multidisciplinary team consultation. The clinicopathological characteristics, surgical outcomes, and oncological results were summarized. Results: All surgeries were successfully completed with negative surgical margins, and no case was required conversion surgery. All patients were fed via nasogastric tubes postoperatively, with a median gastric tube stay of 7 days (range: 2-60 days). No tracheotomy was applied. There were no major complications such as postoperative bleeding. Pathological complete response (pCR) was found in 10 cases (76.9%) among the 13 patients with NACI. The follow-up time was 21 months (range: 10-47 months), and there was no death or distant metastasis. One patient with rT0N3M0 tonsil cancer had local recurrence 5 months after surgery. The 2-year overall survival and 2-year disease-free survival were respectively 100.0% and 93.3% in the 15 patients. Conclusion: NACI combined with TORS provides a safe, effective and minimally invasive treatment for patients with locally advanced oropharyngeal squamous cell carcinoma.

Genome-wide association study of growth curve parameters reveals novel genomic regions and candidate genes associated with metatarsal bone traits in chickens

The growth and development of chicken bones have an enormous impact on the health and production performance of chickens. However, the development pattern and genetic regulation of the chicken skeleton are poorly understood. This study aimed to evaluate metatarsal bone growth and development patterns in chickens via non-linear models, and to identify the genetic determinants of metatarsal bone traits using a genome-wide association study (GWAS) based on growth curve parameters. Data on metatarsal length (MeL) and metatarsal circumference (MeC) were obtained from 471 F2 chickens (generated by crossing broiler sires, derived from a line selected for high abdominal fat, with Baier layer dams) at 4, 6, 8, 10, and 12 weeks of age. Four non-linear models (Gompertz, Logistic, von Bertalanffy, and Brody) were used to fit the MeL and MeC growth curves. Subsequently, the estimated growth curve parameters of the mature MeL or MeC (A), time-scale parameter (b), and maturity rate (K) from the non-linear models were utilized as substitutes for the original bone data in GWAS. The Logistic and Brody models displayed the best goodness-of-fit for MeL and MeC, respectively. Single-trait and multi-trait GWASs based on the growth curve parameters of the Logistic and Brody models revealed 4 618 significant single nucleotide polymorphisms (SNPs), annotated to 332 genes, associated with metatarsal bone traits. The majority of these significant SNPs were located on Gallus gallus chromosome (GGA) 1 (167.433-176.318 Mb), GGA2 (96.791-103.543 Mb), GGA4 (65.003-83.104 Mb) and GGA6 (64.685-95.285 Mb). Notably, we identified 12 novel GWAS loci associated with chicken metatarsal bone traits, encompassing 35 candidate genes. In summary, the combination of single-trait and multi-trait GWASs based on growth curve parameters uncovered numerous genomic regions and candidate genes associated with chicken bone traits. The findings benefit an in-depth understanding of the genetic architecture underlying metatarsal growth and development in chickens.

Distinguishing the functions of canonical strigolactones as rhizospheric signals

Strigolactones (SLs) act as regulators of plant architecture as well as signals in rhizospheric communications. Reduced availability of minerals, particularly phosphorus, leads to an increase in the formation and release of SLs that enable adaptation of root and shoot architecture to nutrient limitation and, simultaneously, attract arbuscular mycorrhizal fungi (AMF) for establishing beneficial symbiosis. Based on their chemical structure, SLs are designated as either canonical or non-canonical; however, the question of whether the two classes are also distinguished in their biological functions remained largely elusive until recently. In this review we summarize the latest advances in SL biosynthesis and highlight new findings pointing to rhizospheric signaling as the major function of canonical SLs.

Abscisic acid inhibits germination of Striga seeds and is released by them likely as a rhizospheric signal supporting host infestation

Seeds of the root parasitic plant Striga hermonthica undergo a conditioning process under humid and warm environments before germinating in response to host-released stimulants, particularly strigolactones (SLs). The plant hormone abscisic acid (ABA) regulates different growth and developmental processes, and stress response; however, its role during Striga seed germination and early interactions with host plants is under-investigated. Here, we show that ABA inhibited Striga seed germination and that hindering its biosynthesis induced conditioning and germination in unconditioned seeds, which was significantly enhanced by treatment with the SL analog rac-GR24. However, the inhibitory effect of ABA remarkably decreased during conditioning, confirming the loss of sensitivity towards ABA in later developmental stages. ABA measurement showed a substantial reduction of its content during the early conditioning stage and a significant increase upon rac-GR24-triggered germination. We observed this increase also in released seed exudates, which was further confirmed by using the Arabidopsis ABA-reporter GUS marker line. Seed exudates of germinated seeds, containing elevated levels of ABA, impaired the germination of surrounding Striga seeds in vitro and promoted root growth of a rice host towards germinated Striga seeds. Application of ABA as a positive control caused similar effects, indicating its function in Striga/Striga and Striga/host communications. In summary, we show that ABA is an essential player during seed dormancy and germination processes in Striga and acts as a rhizospheric signal likely to support host infestation.

Strigolactone biosynthesis in rice can occur via a 9-cis-3-OH-10'-apo-β-carotenal intermediate

Strigolactones (SLs) play a crucial role in regulating plant architecture and mediating rhizosphere interactions. They are synthesized from all-trans-β-carotene converted into the intermediate carlactone (CL) via the intermediate 9-cis-β-apo-10'-carotenal. Recent studies indicate that plants can also synthesize 3-OH-CL from all-trans-β-zeaxanthin via the intermediate 9-cis-3-OH-β-apo-10'-carotenal. However, the question of whether plants can form bioactive SLs from 9-cis-3-OH-β-apo-10'-carotenal remains elusive. In this study, we supplied the 13 C-labeled 9-cis-3-OH-β-apo-10'-carotenal to rice seedlings and monitored the synthesis of SLs using liquid chromatography-mass spectrometry (LC-MS) and Striga bioassay. We further validated the biological activity of 9-cis-3-OH-β-apo-10'-carotenal-derived SLs using the ccd7/d17 SL-deficient mutant, which demonstrated increased Striga seed-germinating activity and partial rescue of tiller numbers and plant height. Our results establish 9-cis-3-OH-β-apo-10'-carotenal as a significant SL biosynthetic intermediate with implications for understanding plant hormonal functions and potential applications in agriculture.

Discovery of New Isotopes ^{160}Os and ^{156}W: Revealing Enhanced Stability of the N=82 Shell Closure on the Neutron-Deficient Side

Using the fusion-evaporation reaction ^{106}Cd(^{58}Ni,4n)^{160}Os and the gas-filled recoil separator SHANS, two new isotopes _{76}^{160}Os and _{74}^{156}W have been identified. The α decay of ^{160}Os, measured with an α-particle energy of 7080(26) keV and a half-life of 201_{-37}^{+58}  μs, is assigned to originate from the ground state. The daughter nucleus ^{156}W is a β^{+} emitter with a half-life of 291_{-61}^{+86}  ms. The newly measured α-decay data allow us to derive α-decay reduced widths (δ^{2}) for the N=84 isotones up to osmium (Z=76), which are found to decrease with increasing atomic number above Z=68. The reduction of δ^{2} is interpreted as evidence for the strengthening of the N=82 shell closure toward the proton drip line, supported by the increase of the neutron-shell gaps predicted in theoretical models.

[Annual review of bronchiectasis research in 2023]

This review focuses on the latest advances in bronchiectasis from October 1st, 2022 to September 30th, 2023, including the etiology, diagnosis, treatment, comorbidities, and management of bronchiectasis in order to provide a reference in clinical diagnosis and treatment, and future research of bronchiectasis for domestic peers.

[Efficacy of 0.05% cyclosporine A combined with vitamin A palmitate in the treatment of meibomian gland dysfunction-related dry eye]

Objective: To evaluate the efficacy of 0.05% cyclosporine A eye drops combined with vitamin A palmitate eye gel in the treatment of dry eye associated with meibomian gland dysfunction (MGD). Methods: A single-center, prospective, randomized, parallel controlled trial design was used to include patients diagnosed with MGD-associated dry eye. The patients were randomly divided into three groups and administered with medications binocularly for 12 weeks. The CsA+VA group was given 0.05% cyclosporine A eye drops twice a day and vitamin A palmitate eye gel three times a day. The CsA+HA group was given 0.05% cyclosporine A eye drops twice a day and 0.1% sodium hyaluronate eye drops three times a day. The HA group was given 0.1% sodium hyaluronate eye drops 3 times a day. The OSDI score, tear meniscus height, fluorescein tear break-up time, Schirmer Ⅰ test (without anesthesia), tear film lipid layer thickness, meibomian gland morphology and function examination, and corneal fluorescein sodium staining score were evaluated at baseline, 4, 8, and 12 weeks after the initiation of the treatment, respectively. Results: A total of 120 patients with MGD-related dry eye met the enrollment criteria, but 10 patients were lost to follow-up; 110 patients were finally included for observation, including 36 patients in the CsA+VA group, 38 in the CsA+HA group and 36 in the HA group. The OSDI score, tear meniscus height, fluorescein tear break-up time and meibomian gland secretion of the 3 groups were significantly improved. At the 12th week of the treatment, the differences of the CsA+VA group [25.45±15.11, (0.30±0.13) mm, (3.72±1.40) s, (5.03±2.52) points] and the CsA+HA group [26.98±16.89, (0.27±0.10) mm, (4.34±1.76) s, (5.11±2.39) points] from the HA group [24.57±11.26, (0.24±0.06) mm, (3.18±1.11) s, (9.11±3.34) points] were statistically significant (P<0.05). Compared with the CsA+HA group [(68.39±26.66) nm], the tear film lipid layer thickness in the CsA+VA group [(72.61±23.65) nm] was significantly increased (P<0.05). In the CsA+VA group, the meibomian gland secretion characters and discharge capacity among patients with severe abnormalities [(6.28±2.59) and (5.89±2.77) points at the 12th week of treatment], moderate abnormalities [(4.27±2.02) and (4.64±2.02) points at the 12th week of treatment] and mild abnormalities [(2.80±0.84) and (2.60±0.55) points at the 12th week of treatment] were significantly different (P<0.05). Conclusion: 0.05% cyclosporine A combined with vitamin A palmitate can significantly improve the symptoms and signs of patients with MGD-related dry eye, especially the tear film lipid layer thickness and the meibomian gland secretion characters and discharge capacity in severe cases.

Integration of rice apocarotenoid profile and expression pattern of Carotenoid Cleavage Dioxygenases reveals a positive effect of β-ionone on mycorrhization

Carotenoids are susceptible to degrading processes initiated by oxidative cleavage reactions mediated by Carotenoid Cleavage Dioxygenases that break their backbone, leading to products called apocarotenoids. These carotenoid-derived metabolites include the phytohormones abscisic acid and strigolactones, and different signaling molecules and growth regulators, which are utilized by plants to coordinate many aspects of their life. Several apocarotenoids have been recruited for the communication between plants and arbuscular mycorrhizal (AM) fungi and as regulators of the establishment of AM symbiosis. However, our knowledge on their biosynthetic pathways and the regulation of their pattern during AM symbiosis is still limited. In this study, we generated a qualitative and quantitative profile of apocarotenoids in roots and shoots of rice plants exposed to high/low phosphate concentrations, and upon AM symbiosis in a time course experiment covering different stages of growth and AM development. To get deeper insights in the biology of apocarotenoids during this plant-fungal symbiosis, we complemented the metabolic profiles by determining the expression pattern of CCD genes, taking advantage of chemometric tools. This analysis revealed the specific profiles of CCD genes and apocarotenoids across different stages of AM symbiosis and phosphate supply conditions, identifying novel reliable markers at both local and systemic levels and indicating a promoting role of β-ionone in AM symbiosis establishment.

[Comparison of short-term safety of two anastomotic techniques when resecting Siewert type II adenocarcinoma of the esophagogastric junction: a multicenter retrospective cohort study]

Objective: In this study, we aimed to compare the short-term safety of two digestive tract reconstruction techniques, laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis, following radical resection of Siewert Type II adenocarcinoma of the esophagogastric junction. Methods: In this retrospective cohort study, we analyzed relevant clinical data of 139 patients who had undergone radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. These included 89 patients treated at the First Affiliated Hospital of Air Force Medical University from November 2021 to July 2023, 36 patients treated at the First Affiliated Hospital of Xi'an Jiaotong University from December 2020 to June 2021, and 14 patients treated at the Yuncheng Central Hospital in Shanxi Province from September 2021 to November 2022. The group consisted of 107 men (77.0%) and 32 women (23.0%) of mean age 62.5±9.3 years. Forty-eight patients underwent laparoscopic total abdominal overlap anastomosis (overlap group), and 91 laparoscopic-assisted end-to-side anastomosis (end-to-side group). Clinical data, surgical information, pathological findings, postoperative recovery, and related complications were compared between the two groups. Results: There were no significant differences in general clinical data between the overlap and end-to-side anastomosis groups (all P>0.05), indicating comparability. There was no significant difference in operation time (267.2±60.1 minutes vs. 262.8±70.6 minutes, t=0.370, P=0.712). However, the intraoperative blood loss in the overlap group (100 [50, 100] mL) was significantly lower compared to the end-to-side group (100[50, 175] mL, Z=2.776, P=0.005). Compared to the end-to-side group, longer distances between the tumor and distal resection margin proximal(1.7±1.0 cm vs. 1.3±0.9 cm, t=2.487, P=0.014) and the tumor and distal resection margin (9.5±2.9 cm vs. 7.9±3.5 cm, t=2.667, P=0.009) were achieved in the overlap group. Compared with the end-to-side group, the overlap group achieved significantly earlier postoperative ambulation (1.0 [1.0, 2.0] days vs. 2.0 [1.0, 3.0] days, Z=3.117, P=0.002), earlier time to first drink (4.7±2.6 days vs. 6.2±3.0 days, t=2.851, P=0.005), and earlier time to first meal (6.0±2.7 days vs. 7.1±3.0 days, t=2.170, P=0.032). However, the hospitalization costs were higher in the overlap group (113, 105.5±37, 766.3) yuan vs. (97, 250.2±27, 746.9) yuan; this difference is significant (t=2.818, P=0.006). There were no significant differences between the two groups in postoperative hospital stay, total number of lymph nodes cleared, or time to first postoperative flatus (all P>0.05). The incidence of surgery-related complications was 22.9%(11/48) in the overlap group and 19.8% (18/91) in the end-to-side group; this difference is not significant (χ²=0.187, P=0.831). Further comparison of complications using the Clavien-Dindo classification also showed no significant differences (Z=0.406, P=0.685). Conclusions: Both laparoscopic total abdominal overlap anastomosis and laparoscopic-assisted end-to-side anastomosis are feasible for radical surgery for Siewert Type II esophagogastric junction adenocarcinoma. Laparoscopic total abdominal overlap anastomosis achieves longer proximal and distal resection margins and better postoperative recovery; however, end-to-side anastomosis is more cost-effective.

Does zaxinone counteract strigolactones in shaping rice architecture?

The cleavage of plant carotenoids leads to apocarotenoids, a group of metabolites including precursors of the hormones strigolactones (SLs) and abscisic acid, regulatory and signaling molecules. Zaxinone is a recently discovered apocarotenoid growth regulator that improves growth and suppress SL biosynthesis in rice (Oryza sativa). To test if zaxinone also counteracts the growth regulatory effects of SLs in rice, we co-supplied zaxinone and the synthetic SL analog rac-GR24 to the rice SL-deficient DWARF17 (d17) mutant. Results showed that co-application of GR24 and zaxinone still rescued d17 phenotype, indicating that zaxinone and GR24 act independently in regulating root and shoot growth and development in rice.

[Application value of questionnaires in the screening obstructive sleep apnea syndrome in pregnancy across trimesters]

Objective: To evaluate the clinical utility value of questionnaires of Berlin, STOP, STOP-Bang (SBQ), Epworth Sleepiness Scale (ESS) in screening obstructive sleep apnea syndrome (OSAS) in pregnant women of different trimesters. Methods: Consecutive pregnant women at high risk for OSAS were enrolled from January, 2021 to April, 2022 at the obstetric clinic of Peking University People's Hospital. They completed questionnaires of Berlin, STOP, SBQ, ESS and also underwent an overnight polysomnography (PSG). To evaluate the accuracy of questionnaires of Berlin, STOP, SBQ, ESS, sensitivity, specificity, positive predictive values, negative predictive values and the area under the receiver operating characteristics (ROC) curve of these questionnaires in pregnancy across trimesters (Pregnancy 1-15 weeks was the first stage, pregnancy 16-27 weeks was the second stage, and pregnancy 28-40 weeks was the third stage) were calculated. Results: A total of 100 pregnant women [(34.5±4.3) years old (26-46 years old)] were included in this study, including 20, 35 and 45 pregnant women in the first, second and third trimester of pregnancy, respectively. Based on PSG results, 45 (45%) of 100 pregnant women were diagnosed with OSAS. The overall predictive values of the four questionnaires were not good, area under[AUC(95%CI)] the ROC curve ESS, Berlin questionnaire STOP and SBQ were 0.54(0.43, 0.66), 0.59 (0.47, 0.70), 0.62(0.51, 0.73) and 0.61 (0.49, 0.72), respectively, sensitivity was 35.6%, 65.9%, 48.9%, 28.9%, specificity was 71.7%, 52.5%, 73.6%, 92.5%. When categorized according to trimesters, the predicted values of the four questionnaires increased in the first trimester, the AUC (95%CI) of STOP questionnaire was 0.81 (0.61, 1.00), sensitivity was 75.0%, specificity was 87.5%. Conclusion: The overall predictive power of the four screening questionnaires is limited in pregnant women. But predictive value of STOP questionnaire is acceptable in the first trimester.

First observation of fluid-like eddy-dominant bursty bulk flow turbulence in the Earth's tail plasma sheet

Turbulence is a ubiquitous phenomenon in neutral and conductive fluids. According to classical theory, turbulence is a rotating flow containing vortices of different scales. Eddies play a fundamental role in the nonlinear cascade of kinetic energy at different scales in turbulent flow. In conductive fluids, the Alfvénic/kinetic Alfvénic wave (AW/KAW) is the new "cell" of magnetohydrodynamic (MHD) turbulence (frozen-in condition). Wave energy, which has equal kinetic and magnetic energy, is redistributed among multiple-scale Fourier modes and transferred from the large MHD scale to the small kinetic scale through the collision of counter-propagating Alfvénic wave packages propagating along the magnetic field line. Fluid-like eddy-dominant plasma flow turbulence has never been found in space since the launch of the first satellite in 1957. In this paper, we report the first observation of eddy-dominant turbulence within magnetic reconnection-generated fast flow in the Earth's tail plasma sheet by the Magnetospheric Multiscale Spacecraft (MMS). In eddy-dominant turbulent reconnection jet, ions dominate the flow field while electrons dominate current and magnetic fluctuations. Our findings shed new light on the nonlinear kinetic and magnetic energy cascade in MHD turbulence.

[Effects of electric welding on hearing loss and respiratory damage]

Objective: To investigate the occupational health status of electric welding workers and explore the effects of electric welding on hearing loss and respiratory damage. Methods: From August to December 2021, the cluster sampling method was used to select workers from an automobile manufacturer in Guangzhou City as research subjects: 636 welding workers in the welding workshop as the welding group, 757 assembly workers in the engine workshop and the final assembly workshop exposed to pure noise as the assembly group. Occupational disease hazard factors were detected for welding positions and assembly positions, and occupational health examination was carried out for research subjects. The occupational health status, the trends of hearing loss and respiratory abnormalities with working age were compared and analyzed between the two groups. Binary logistic regression was used to analyze the association between hearing loss and respiratory abnormalities in welding workers. Results: The excess rates of welding fumes, manganese and its compounds in the welding position were both 9.68% (3/31). Its noise exposure intensity [ (85.36±2.68) dB (A) ] and excess rate [48.39% (15/31) ] were not significantly different from those in the assembly position [ (84.86±3.28) dB (A) and 43.24% (16/37) ] (P>0.05). The results of the occupational health examination showed that the detection rates of hearing loss, digital radiography (DR) chest X-ray abnormality, alanine aminotransferase abnormality, deazelaic aminotransferase abnormality and white blood cell count abnormality of workers in the welding group were higher than those in the assembly group (P<0.05). The detection rates of hearing loss, DR chest X-ray abnormality, pulmonary ventilation abnormality in the welding group and the detection rate of hearing loss in the assembly group increased with the working age of the workers (P<0.05). The hearing loss detection rate and DR chest X-ray abnormality detection rate of the workers with ≥9 years working age in the welding group were both higher than those in the assembly group workers with same working age (P<0.05). The binary logistic regression analysis showed that abnormal pulmonary ventilation and abnormal DR chest X-ray were the risk factors for hearing loss in welding workers (OR=10.83, 95%CI: 7.31-16.06; OR=16.59, 95%CI: 5.72-48.10; P<0.05) . Conclusion: Hearing loss and respiratory damage are prominent problems among welding workers, and the detection rates of abnormality increase with the working age of the workers. Hearing loss in welding workers is associated with abnormal pulmonary ventilation and abnormal DR chest X-ray.

Disruption of the rice 4-DEOXYOROBANCHOL HYDROXYLASE unravels specific functions of canonical strigolactones

Strigolactones (SLs) regulate many developmental processes, including shoot-branching/tillering, and mediate rhizospheric interactions. SLs originate from carlactone (CL) and are structurally diverse, divided into a canonical and a noncanonical subfamily. Rice contains two canonical SLs, 4-deoxyorobanchol (4DO) and orobanchol (Oro), which are common in different plant species. The cytochrome P450 OsMAX1-900 forms 4DO from CL through repeated oxygenation and ring closure, while the homologous enzyme OsMAX1-1400 hydroxylates 4DO into Oro. To better understand the biological function of 4DO and Oro, we generated CRISPR/Cas9 mutants disrupted in OsMAX1-1400 or in both OsMAX1-900 and OsMAX1-1400. The loss of OsMAX1-1400 activity led to a complete lack of Oro and an accumulation of its precursor 4DO. Moreover, Os1400 mutants showed shorter plant height, panicle and panicle base length, but no tillering phenotype. Hormone quantification and transcriptome analysis of Os1400 mutants revealed elevated auxin levels and changes in the expression of auxin-related, as well as of SL biosynthetic genes. Interestingly, the Os900/1400 double mutant lacking both Oro and 4DO did not show the observed Os1400 architectural phenotypes, indicating their being a result of 4DO accumulation. Treatment of wild-type plants with 4DO confirmed this assumption. A comparison of the Striga seed germinating activity and the mycorrhization of Os900, Os900/1400, and Os1400 loss-of-function mutants demonstrated that the germination activity positively correlates with 4DO content while disrupting OsMAX1-1400 has a negative impact on mycorrhizal symbiosis. Taken together, our paper deciphers the biological function of canonical SLs in rice and reveals their particular contributions to establishing architecture and rhizospheric communications.

Zaxinone mimics (MiZax) efficiently promote growth and production of potato and strawberry plants under desert climate conditions

Climate changes and the rapid expanding human population have become critical concerns for global food security. One of the promising solutions is the employment of plant growth regulators (PGRs) for increasing crop yield and overcoming adverse growth conditions, such as desert climate. Recently, the apocarotenoid zaxinone and its two mimics (MiZax3 and MiZax5) have shown a promising growth-promoting activity in cereals and vegetable crops under greenhouse and field conditions. Herein, we further investigated the effect of MiZax3 and MiZax5, at different concentrations (5 and 10 µM in 2021; 2.5 and 5 µM in 2022), on the growth and yield of the two valuable vegetable crops, potato and strawberry, in the Kingdom of Saudi of Arabia. Application of both MiZax significantly increased plant agronomic traits, yield components and total yield, in five independent field trials from 2021 to 2022. Remarkably, the amount of applied MiZax was far less than humic acid, a widely applied commercial compound used here for comparison. Hence, our results indicate that MiZax are very promising PGRs that can be applied to promote the growth and yield of vegetable crops even under desert conditions and at relatively low concentrations.

Fixed-Field IMRT for Cervix Carcinoma Patients on an MR-LINAC Platform: Dosimetric Feasibility and Challenges

PURPOSE/OBJECTIVE(S)

To investigate the impact of MR-LINAC performance characteristics and inverse planning implementation on the feasibility of fixed-field IMRT for cervix carcinoma patients by benchmarking MR-LINAC plans against clinically used VMAT plans in a single institution study and multi-institutional treatment planning challenge.

MATERIALS/METHODS

For 10 cervix cancer patients who had previously received Linac-based VMAT, new treatment plans were optimized for MR-LINAC IMRT using 6X FFF fixed fields with maximum available field size of 27.4 x 24.1 cm2. Dose optimization was performed on the clinically used planning CT and structure set. Prescribed dose was 48.6 Gy in 27 fractions for all patients with 6 patients receiving an additional integrated boost for a total of 58.05 Gy to involved nodes. Constraints were based on our institutional protocol as per Table 1. IMRT delivery time was limited to 20 min. Original clinically used VMAT plans were generated on Eclipse (Varian Medical System) using 3 to 4 arcs. For the multi-institutional planning challenge, the data set from a single patient was anonymized and shared to participants. Participants used a single MR-based Linac planning platform to generate a plan based on our institutional constraints, with maximum treatment time limited to 20 min. For all analyses, a paired samples t-test was used to compare the significance defined at p < 0.05.

RESULTS

For MR-LINAC plans, the mean number of fields used was 23, mean number of segments 229, and the average estimated treatment delivery time was 17.3 minutes. MR-LINAC plans showed a significantly higher heterogeneity and dose to organs at risk compared to VMAT plans (Table 1). For the planning challenge, a total of 30 participants registered interest. Of this, seven plans were submitted to the challenge. On average, participants generated a plan that would be acceptable based on our institutional constraints (Table 1). However, the volumetric dose to bowel and pelvic bones were higher on MR-LINAC plans compared to the reference VMAT plan.

CONCLUSION

MR-LINAC fixed-field IMRT for cervix cancer patients is feasible but system constraints and optimization implementation result in greater dose heterogeneity and worse organ-at-risk sparing compared to Linac based VMAT. Further research is needed to determine if potential reduction of treatment margins, allowed by better MRI soft-tissue visualization, will result in MR-LINAC IMRT superior to Linac VMAT.

Clinical Implementation of an Automated IMRT/VMAT Treatment Planning Tool

PURPOSE/OBJECTIVE(S)

To create an in-house automated treatment planning tool for IMRT/VMAT treatments and evaluate the dosimetric plan quality against manually generated plans.

MATERIALS/METHODS

A scripting application programming interface is employed to interact with a commercial treatment planning system (TPS) to implement automatic plan evaluation and update optimization parameters by mimicking the human planning process. The automated planning performs in an iterative fashion until reaching an acceptable tradeoff among target coverage/dose homogeneity and sparing of critical organs at risk. In each iteration, the dose constraints, priorities, and optimization structures for are automatically updated based on the results of the current iteration. Twenty previously treated plans (10 prostate and 10 head and neck), were preliminarily used to evaluate the performance of the automated planning tool. The differences in target and organ-at-risk metrics from the manually generated clinical plans were analyzed using paired t-test to evaluate clinical acceptability of tour automated planning tool. The current in-house-developed automated planning solution is able to create plans for different disease sites, including head & neck, prostate, pelvis, and lung. So far, the VMAT plans for more than 150 different cases have been generated with the tool. The results for these were also evaluated.

RESULTS

Compared to the manually generated clinical head and neck plans, all auto plans achieved PTV D95% coverage and critical organs at risk sparing without statistically significant change in average global Dmax (107.4% for manual vs 107.3% for automated plans). The auto-planning solution provided reduced maximum doses to brainstem and spinal cord (average reductions with standard deviations of 5.1 ± 2.6 Gy and 2.9 ± 1.4 Gy, respectively, all p <0.03), reduced average mean doses to contralateral parotid, ipsilateral parotid, contralateral submandibular gland, pharynx, esophagus, cochleae (reductions of 2.2 ± 2.9 Gy, 4.8 ± 4.7 Gy, 3.6 ± 5.2 Gy, 2.0 ± 7.1 Gy, 3.9 ± 2.6 Gy, 3.8 ± 5.0 Gy, respectively, all p < 0.045). Similar results were observed for the prostate plans. With the same PTV coverage and without statistically significant change in average global Dmax (106.5% for manual vs 106.8% for automated plans), the automated solution provided superior sparing for both bladder and rectum. Bladder V75, V70, V65 were reduced by 0.6% ± 2.1%, 0.8% ± 2.5%, and 0.9% ± 2.9% (all p <0.04), respectively. Rectum V75, V70, V65, V60 were reduced by 1.0% ± 2.3%, 1.2% ± 2.8%, 1.3% ± 3.2%, 1.6% ± 3.6% (all p < 0.01), respectively.

CONCLUSION

Our automated treatment planning solution is capable of efficiently generating VMAT plans for different disease sites with superior dosimetric indices compared to manually generated plans. Our tool is integrated within a commercial TPS platform, so it has the advantage of seamless adoption into the standard workflow to improve plan quality and treatment planning efficiency in our clinic.

The Lyman Normal Tissue Complication Probability Model and Risk Prediction for Temporal Lobe Injury after Re-Irradiation in Patients with Recurrent Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

The risk of temporal lobe injury (TLI) in recurrent nasopharyngeal carcinoma (rNPC) patients with intensity-modulated radiation therapy (IMRT) is high. We aimed to construct the normal tissue complication probability (NTCP) model for TLI of rNPC and establish a risk predictive model.

MATERIALS/METHODS

We retrospectively analyzed 103 patients with rNPC who had received two courses of IMRT in our institution. The 206 temporal lobes (TLs) of these patients were randomly divided into a training (n = 144) and validation group (n = 62). We determined the mean value of the following parameters to construct the Lyman NTCP model: TD50(1) (the dose with a 50% probability of complications to an organ when all volumes are irradiated), m [steepness of the dose-response at TD50(1)], and n (the parameter related to volume effect). The most predictive dosimetric parameter and clinical variables were integrated in Cox proportional hazards models. A nomogram was developed for predicting risk of TLs.

RESULTS

The parameters of the fitted NTCP model were TD50(1) = 107.84 Gy (95% confidence interval (CI), [97.15, 118.54]), m = 0.16 (95% CI, [0.14, 0.19]), and n = 0.04 (95% CI, [0.01, 0.06]). The cumulative dose delivered to 0.1 cm3 of temporal lobe volume (D0.1cc-c) was the most predictive dosimetric parameter for TLI. The Kaplan-Meier curves showed a significant difference in 2-year TLI-free survival among different risk groups according to the total score of nomograms.

CONCLUSION

The TD50(1) of TLI in patients with rNPC is 107.84 Gy in Lyman NTCP model. The nomogram model can accurately predict the risk of TLI for individual.

Prospective Clinical Adoption of Artificial Intelligence for Organ Contouring in Head and Neck Radiation Treatment Planning

PURPOSE/OBJECTIVE(S)

Patients that undergo head and neck (H&N) radiation therapy (RT) require laborious delineation of organs-at-risk (OARs) on computed tomography (CT) scans in a treatment planning system (TPS) to minimize radiation to normal tissue. This task can be completed rapidly and accurately with recently developed artificial intelligence-based semantic segmentation models. The current study aims to deploy and evaluate a strategy for improving clinical practice with this technology.

MATERIALS/METHODS

Deep learning models were trained and tested with CT scans and OAR contours from previous H&N RT cases at our clinic. Two medical physicists vetted the models and selected a 2.5D U-Net for further implementation. The model was embedded in a dedicated server at the hospital, programmed to read H&N CT scans staged for import into the TPS, generate auto-contours, and write them into a TPS-compatible format made available alongside the scan. In the pilot implementation, the auto-contouring service was utilized for more than 60 cases, prospectively. The auto-contours were quantitatively evaluated against the treatment-approved contours to determine how much modification was performed by the clinical team.

RESULTS

The 2.5D U-Net selected for clinical integration segments 21 OARs in less than 3 minutes per scan. Across all the prospective cases, the mean Dice score and mean 95th percentile Hausdorff distance (mm) between the auto-contour and treatment-approved contour for each of the 21 OARs were as follows, respectively: brainstem (0.93, 1.94), optic chiasm (0.70, 2.96), left cochlea (0.69, 2.37), right cochlea (0.68, 2.44), esophagus (0.88, 2.46), left globe (0.93, 1.50), right globe (0.93, 1.63), glottis (0.91, 2.13), larynx (0.93, 2.76), mandible (0.90, 4.86), left optic nerve (0.78, 1.64), right optic nerve (0.82, 1.65), oral cavity (0.86, 8.46), left parotid gland (0.91, 2.78), right parotid gland (0.91, 2.39), pharynx (0.85, 2.39), spinal cord (0.87, 2.27), left submandibular gland (0.85, 3.46), right submandibular gland (0.83, 3.69), left temporal lobe (0.94, 2.20), and right temporal lobe (0.95, 2.09). The auto-contours for the optic chiasm, optic nerves, cochleas, and submandibular glands differed substantially from the final contours, a finding corroborated by the clinical team; the rest were clinically acceptable with minor or no edits necessary.

CONCLUSION

The proposed strategy provides a sophisticated starting point for treatment planning that has garnered overall favorable feedback from the participating radiation oncologists and dosimetrists. Consequently, the technique is being extended to other treatment sites.

Parametric Response Mapping of Co-Registered Ivim MRI and PET to Identify Radioresistant Sub-Volumes in Locally Advanced Cervical Carcinoma Undergoing CCRT

PURPOSE/OBJECTIVE(S)

To investigate parametric response mapping (PRM) of co-registered positron emission tomography (PET) and intravoxel incoherent motion (IVIM) MRI in locally advanced cervical carcinoma patients to identify sub-volumes that may predict treatment response to adjuvant concurrent chemoradiation therapy (CCRT).

MATERIALS/METHODS

Pre- and on-treatment (∼after four weeks of CCRT) diffusion weighted images (DWIs) MRI and pre-treatment PET were performed on 20 cervical cancer patients (median [range] age: 63 [41 to 85]; FIGO staging: 3 IIB, 1 IIIB, 10 IIIC1, 4 IIIC2, 2 IVA; histology: 11 squamous cell carcinoma, 4 endocervical adenocarcinoma; LN status: 4 negative, 16 positive). IVIM MRI maps were generated by Bayesian fitting of a two-compartment IVIM model to the DWIs to produce three-dimensional diffusion coefficient (D) and perfusion fraction (f). Three-dimensional IVIM D and f maps were co-registered to PET standardized uptake value (SUV) maps. Population means of PET SUV, IVIM D and f from pre-treatment scans were calculated to generate thresholds to identify low versus high metabolic (μSUV) regions, low versus high diffused (μD) regions as well as low versus high perfused (μf) regions, respectively. PRM maps were generated using voxel-wise joint histogram analysis to classify voxels within the tumor as highly metabolic and with low cellular density (SUV↑D↑), highly metabolic and with high cellular density (SUV↑D↓), metabolically inactive and with high cellular density (SUV↓D↓), or metabolically inactive and with low cellular density (SUV↓D↑) tissue based on the population mean thresholds. Similar PRM maps were generated using the joint histogram analysis with SUV and f. Summary statistics for these and other imaging parameters were calculated pre- and on-treatment. Univariate analysis was performed to determine relationships between relative change in gross tumor volume (ΔGTV) and pre-treatment imaging measurements.

RESULTS

In tumors, on- versus pre-treatment tumor volume (p<.001) significantly decreased, while IVIM f (p = .002) and D (p = .03) significantly increased. Pre-treatment tumor volume (r = .45, p = .04) and PRM SUV↑D↓ (r = .65, p = .002) regions were positively related with ΔGTV, while pre-treatment IVIM D (r = -.64, p = .002), PRM SUV↓f↑ (r = -.52, p = .02) and PRM SUV↓D↑ (r = -.74, p<.001) regions were negatively related with ΔGTV. The latter PRM result suggests that larger regions of low cellular density (as represented by elevated D) + low metabolism result in a reduced change in tumor volume on-treatment, potentially representing a radioresistant sub-volume.

CONCLUSION

PRM, generated from PET and IVIM MRI, was applied to patients with locally advanced cervical carcinoma and radioresistant sub-volumes were identified which may predict treatment response. The complementary information provided from PET and IVIM, combined using PRM, may assist in decision-making to individualize therapies, such as with image guided brachytherapy, to improve patient outcomes.

Prediction of Progression After Cervix Cancer Radiotherapy Using a Machine-Learning Model on Pre-Treatment MRI

PURPOSE/OBJECTIVE(S)

MRI may be useful to identify women with cervical cancer at high risk of disease progression to test strategies of treatment intensification. The purpose of this study was to determine the value of a machine-learning model built on pre-treatment MRI for prediction of risk of progression after radiation therapy.

MATERIALS/METHODS

MagneticResonance Imaging (MRI) data for women with cervical cancer was collected from The Cancer Genome Atlas Cervical Squamous Cell Carcinoma and Endocervical Adenocarcinoma Collection (TCGA-CESC) on the Cancer Imaging Archive (TCIA), which reported clinical, treatment, and imaging data from a single institution. 27 patients who had received radiation for cervical cancer were selected for input into a custom 3-D Residual Neural Network (ResNet) model with added custom layers specific to DICOM data in tensorflow python package. One T2 MRI per patient was used to predict recurrence free survival after radiation treatment, where patients were predicted to be "high risk" or "low risk" for disease recurrence as the output of the model. All slices of the T2 MRI were used. The model was validated using five-fold cross validation; 80% of the data was used to train each fold and 20% was used for testing. Final model statistical significance was confirmed through shuffle test at the p < 0.01 level. The clinical outcomes of patients and the model's "low-risk" and "high-risk" prediction were compared.

RESULTS

There were 27 patients in the study with mean age of 51 years (range 29-79). 20 patients had squamous cell carcinoma and 7 patients had adenocarcinoma. The stage breakdown consisted of 9 women IB, 2 IIA, 9 IIB, 2 IIIA, 2 IIIB, and 3 stage IV. 10 women were treated with radiation alone and 17 with chemo-radiation. 5 women received surgery in addition to radiation or chemoradiation. 21 patients received brachytherapy. Median follow-up of patients was 29 months (range 3-64). The model predicted 7 patients as "high risk" for recurrence; all 7 developed a recurrence during follow up. None of the 20 patients predicted to be "low risk" developed disease recurrence. Among all patients in the study, the two-year progression free survival (PFS) was 82.0%. Patients identified as "low risk" and "high risk" by model had two-year PFS of 100% and 43%, respectively. Among patients with recurrence, 3 developed local recurrence and 4 developed distant metastases. The ResNet model achieved cross-validated accuracy of 92% for prediction of progression-free survival (p<0.01).

CONCLUSION

A 3-D ResNet machine-learning model using pretreatment MRI image data can accurately predict clinical outcomes for cervical cancer following radiation therapy. Future work to confirm generalizability should focus on validation with a larger clinical dataset.

[Relationships between hypertensive disorders in pregnancy and obstructive sleep apnea syndrome]

Objective: To investigate the impact of obstructive sleep apnea syndrome (OSAS) on pregnancy outcomes, especially the relationship between OSAS and hypertensive disorders in pregnancy (HDP). Methods: A total of 228 pregnant women with high risk of OSAS who underwent sleep monitoring during pregnancy in Peking University People's Hospital from January 2021 to April 2022 were collected by reviewing their medical records for retrospective analysis. According to the diagnosis of OSAS, the pregnant women were divided into OSAS group (105 cases) and non-OSAS group (123 cases). The non-parametric Mann-Whitney U test, χ2 test or Fisher's exact test were used to compare the general data and maternal and fetal outcomes between the two groups, and the occurrence of each type of HDP was further compared. Results: (1) Compared with the non-OSAS group, the median pre-pregnancy body mass index (23.6 vs 27.6 kg/m2) and the proportion of snoring [28.9% (33/114) vs 59.2% (61/103)] in the OSAS group were higher, and the differences were both statistically significant (both P<0.001). (2) The incidence of HDP [67.6% (71/105) vs 39.0% (48/123)] and gestational diabetes mellitus [GDM; 40.0% (42/105) vs 26.8% (33/123)] of pregnant women in the OSAS group were higher than those in the non-OSAS group, and the median delivery week was shorter than that in the non-OSAS group (38.4 vs 39.0 weeks). The differences were all statistically significant (all P<0.05). Between-group differences for the delivery way, postpartum hemorrhage, the rate of intensive care unit admission, preterm birth, small for gestational age infants, neonatal asphyxia, the rate of neonatal intensive care unit admission, newborn birth weight and the proportion of umbilical artery blood pH<7.00 were not statistically significant (all P>0.05). (3) Compared with the non-OSAS group, the incidence of chronic hypertension [11.4% (14/123) vs 22.9% (24/105)] and chronic hypertension with superimposed pre-eclampsia [11.4% (14/123) vs 30.5% (32/105)] were higher in the OSAS group, and the differences were both statistically significant (both P<0.01). Conclusion: OSAS is related to HDP (especially chronic hypertension and chronic hypertension with superimposed pre-eclampsia) and GDM, which could provide a practical basis for the screening, diagnosis and treatment of OSAS in pregnant women at high risk.

[Dose-dense paclitaxel plus carboplatin in combination with trastuzumab neoadjuvant versus standard adjuvant therapy in human epidermal growth factor receptor-2 positive and hormone receptor negative breast cancer: a prospective cohort study]

Objective: To provide survival evidence of anthracycline-free neoadjuvant chemotherapy for patients with stages Ⅱ-Ⅲ human epidermal growth factor receptor-2 (HER-2) positive and hormone receptor (HR) negative breast cancer. Methods: The prospective cohort study was conducted at the Department of Medical Oncology of Cancer Hospital, Chinese Academy of Medical Sciences. Patients with HER-2 positive and HR negative breast cancer in stages Ⅱ-Ⅲ were enrolled to receive neoadjuvant therapy (NAT) of dose-dense paclitaxel (175 mg/m(2)) plus carboplatin (AUC=4.0) biweekly for 6 cycles in combination with trastuzumab (PCbH), and matched patients who received standard adjuvant therapy of physicians' choice were recruited for survival and safety comparison. Results: From July 2013 to November 2019, 166 patients were included (neoadjuvant 51, adjuvant 115). Compared with those who received adjuvant therapy, patients receiving NAT were younger (<35 years: 19.6% vs 5.2%, P=0.014), had larger tumors (T3: 62.7% vs 7.8%, P<0.001) and more advanced diseases (stage ⅡA: 2.0% vs 41.7%, P<0.001). Patients in the neoadjuvant group all received surgery, and 96 (83.5%) in the adjuvant group received anthracycline-and-taxane-containing regimens. A total of 98 patients (49 pairs) were matched, and the covariates between the two groups were acceptably balanced. Within a median follow-up of 46.5 (range, 14-87) months, the 4-year recurrence-free survival (RFS) rate among patients who received NAT was 73.3% (95% CI: 59.0%-87.6%), versus 80.6% (95% CI: 67.9%-93.3%) among those in the adjuvant group without statistical difference (P=0.418). A similar result was observed for the 4-year overall survival (OS) [neoadjuvant versus adjuvant: 91.5% (95% CI: 81.7%-100.0%) vs 97.8% (95% CI: 93.5%-100.0%), P=0.314]. Compared with standard adjuvant therapy, PCbH was related to less neutropenia and better cardiac safety. Conclusions: These results support the consideration of anthracycline-free neoadjuvant chemotherapy combined with anti-HER-2 therapy for patients with stages Ⅱ-Ⅲ HER-2-positive and HR-negative breast cancer. Optimized regimens with both efficacy and safety are needed and to be further investigated.

New Series of Zaxinone Mimics (MiZax) for Fundamental and Applied Research

The apocarotenoid zaxinone is a recently discovered regulatory metabolite required for proper rice growth and development. In addition, zaxinone and its two mimics (MiZax3 and MiZax5) were shown to have a remarkable growth-promoting activity on crops and a capability to reduce infestation by the root parasitic plant Striga through decreasing strigolactone (SL) production, suggesting their potential for application in agriculture and horticulture. In the present study, we developed a new series of MiZax via structural modification of the two potent zaxinone mimics (MiZax3 and MiZax5) and evaluated their effect on plant growth and Striga infestation. In general, the structural modifications to MiZax3 and MiZax5 did not additionally improve their overall performance but caused an increase in certain activities. In conclusion, MiZax5 and especially MiZax3 remain the likely most efficient zaxinone mimics for controlling Striga infestation.

Disruption of the cytochrome CYP711A5 gene reveals MAX1 redundancy in rice strigolactone biosynthesis

Strigolactones (SLs) inhibit shoot branching/tillering and are secreted by plant roots as a signal to attract symbiotic mycorrhizal fungi in the rhizosphere, particularly under phosphate starvation. However, SLs are also hijacked by root parasitic weeds as inducer for the germination of their seeds. There are around 35 natural SLs divided, based on their structures, into canonical and non-canonical SLs. Cytochrome P450 enzymes of the 711 clade, such as MORE AXILLARY GROWTH1 (MAX1) in Arabidopsis, are a major driver of SL structural diversity. Monocots, such as rice, contain several MAX1 homologs that participate in SL biosynthesis. To investigate the function of OsMAX1-1900 in planta, we generated CRISPR/Cas9 mutants disrupted in the corresponding gene. Characterizing of the generated mutants at metabolite and phenotype level suggests that OsMAX1-1900 loss-of-function does neither affect the SL pattern nor rice architecture, indicating functional redundancy among rice MAX1 homologs.

[Analysis of risk factors of radiation-induced toxicity in limited-stage small cell lung cancer treated with hypofractionated intensity-modulated radiotherapy]

Objective: To compare the incidence of radiation-related toxicities between conventional and hypofractionated intensity-modulated radiation therapy (IMRT) for limited-stage small cell lung cancer (SCLC), and to explore the risk factors of hypofractionated radiotherapy-induced toxicities. Methods: Data were retrospectively collected from consecutive limited-stage SCLC patients treated with definitive concurrent chemoradiotherapy in Cancer Hospital of Chinese Academy of Medical Sciences from March 2016 to April 2022. The enrolled patients were divided into two groups according to radiation fractionated regimens. Common Terminology Criteria for Adverse Events (CTCAE, version 5.0) was used to evaluate the grade of radiation esophagus injuries and lung injuries. Logistic regression analyses were used to identify factors associated with radiation-related toxicities in the hypofractionated radiotherapy group. Results: Among 211 enrolled patients, 108 cases underwent conventional IMRT and 103 patients received hypofractionated IMRT. The cumulative incidences of acute esophagitis grade ≥2 [38.9% (42/108) vs 35.0% (36/103), P=0.895] and grade ≥ 3 [1.9% (2/108) vs 5.8% (6/103), P=0.132] were similar between conventional and hypofractionated IMRT group. Late esophagus injuries grade ≥2 occurred in one patient in either group. No differences in the cumulative incidence of acute pneumonitis grade ≥2[12.0% (13/108) vs 5.8% (6/103), P=0.172] and late lung injuries grade ≥2[5.6% (6/108) vs 10.7% (11/103), P=0.277] were observed. There was no grade ≥3 lung injuries occurred in either group. Using multiple regression analysis, mean esophageal dose ≥13 Gy (OR=3.33, 95% CI: 1.23-9.01, P=0.018) and the overlapping volume between planning target volume (PTV) and esophageal ≥8 cm(3)(OR=3.99, 95% CI: 1.24-12.79, P=0.020) were identified as the independent risk factors associated with acute esophagitis grade ≥2 in the hypofractionated radiotherapy group. Acute pneumonitis grade ≥2 was correlated with presence of chronic obstructive pulmonary disease (COPD, P=0.025). Late lung injuries grade ≥2 was correlated with tumor location(P=0.036). Conclusions: Hypofractionated IMRT are tolerated with manageable toxicities for limited-stage SCLC patients treated with IMRT. Mean esophageal dose and the overlapping volume between PTV and esophageal are independently predictive factors of acute esophagitis grade ≥2, and COPD and tumor location are valuable factors of lung injuries for limited-stage SCLC patients receiving hyofractionated radiotherapy. Prospective studies are needed to confirm these results.

[The prospect and challenge of liquid biopsy in the diagnosis and treatment of chest malignancy]

In recent years, the incidence of chest malignant tumors in China has increased year by year, which has seriously threatened the health problems of people. Among them, early screening and intervention of patients with chest malignancies is the key to cancer prevention. Early detection, early diagnosis, and early treatment as the "three early prevention" of clinical practice are conducive to improve the survival rate of tumor patients. As a non-invasive and real-time reflection of tumor status, liquid biopsy has gradually received attention in clinical diagnosis and treatment. Circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) and exosomes as liquid biopsy "Three carriages" are not only widely used in the diagnosis, monitoring and prognostic evaluation of chest malignancies, but also face many unknown challenges. In this article, the application of liquid biopsy in chest malignancies in recent years is elaborated in detail, which provides a reference for the formulation of clinical tumor prevention and diagnosis and treatment strategies.

[Spatial correlation between the prevalence of dental fluorosis and the chemical elemental composition of drinking water sources in a typical coal-fired pollution fluorosis area]

Objective: To investigate the spatial distribution characteristics and correlation between the prevalence of dental fluorosis and the chemical elemental composition of drinking water sources in coal-fired fluorosis areas. Methods: Based on the survey data on the prevalence of dental fluorosis at CDC in Guizhou Province in 2022, 274 original surface drinking water sources were collected in typical coal-fired fluorosis areas, and fluoride (F), calcium (Ca), magnesium (Mg), aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), molybdenum (Mo), cadmium (Cd), barium (Ba), lead (Pb) 17 elements; apply Moran's I index, Getis-Ord Gi* hotspot analysis of the global spatial autocorrelation of chemical elements in drinking water and the degree of aggregation of each element on the local area, and correlation analysis with the prevalence of dental fluorosis in the region. Results: Except for Cu, Zn, and Cd, global spatial autocorrelation Moran's I was negative, and all other elements were positive. F, Ca, Al, Ti, As, Mo, Cd, and Cu elements showed high values of aggregation in the southeastern low-altitude area; Mg, Ba, Pb, Cr, Mn, and Fe elements were mainly aggregated in the central altitude terrain transition area, Zn and Se elements in water sources are significantly positively correlated with the prevalence of dental fluorosis (P<0.05). In contrast, F, Mg, Al, Ti, As, Mo, Cd, Ba, and Pb elements negatively correlate (P<0.05). Elements in the central region were high-high aggregation, as a hot spot aggregation area with high disease incidence, while F, Al, Mn, Mo, Cd, and Ba elements in the western region were low-low aggregation, as a cold spot aggregation area with a low incidence of fluorosis. Conclusions: The risk of population fluoride exposure in surface drinking water sources is shallow. However, the chemical element content of drinking water sources in coal-fired polluted endemic fluorosis areas has prominent spatial geographical distribution characteristics. There is a significant spatial aggregation effect with the prevalence of dental fluorosis, which may play a synergistic or antagonistic effect on the occurrence and prevalence of dental fluorosis.

[Preliminary experience of gasless transoral vestibular robotic thyroidectomy]

Objective: To explore the feasibility and safety of the gasless transoral vestibular robotic thyroidectomy using skin suspension. Methods: The clinical data of 20 patients underwent gasless transoral vestibular robotic thyroidectomy in the Department of Otorhinolaryngology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University from February 2022 to May 2022 were retrospectively analyzed. Among them, 18 were females and 2 were males, aged (38.7±8.0) years old. The intraoperative blood loss, operation time, postoperative hospital stay, postoperative drainage volume, postoperative pain visual analogue scale (VAS) score, postoperative swallowing function swallowing impairment score-6 (SIS-6), postoperative aesthetic VAS score, postoperative voice handicap index-10 (VHI-10) voice quality, postoperative pathology and complications were recorded. SPSS 25.0 was used for statistical analysis of the data. Results: The operations were successfully completed without conversion to open surgery in all patients. Pathological examination showed papillary thyroid carcinoma in 18 cases, retrosternal nodular goiter in 1 case, and cystic change in goiter in 1 case. The operative time for thyroid cancer was 161.50 (152.75, 182.50) min [M (P₂₅, P₇₅), the same below] and the average operative time for benign thyroid diseases was 166.50 minutes. The intraoperative blood loss 25.00 (21.25, 30.00) ml. In 18 cases of thyroid cancer, the mean diameter of the tumors was (7.22±2.02) mm, and lymph nodes (6.56±2.14) were dissected in the central region, with a lymph node metastasis rate of 61.11%. The postoperative pain VAS score was 3.00 (2.25, 4.00) points at 24 hours, the mean postoperative drainage volume was (118.35±24.32) ml, the postoperative hospital stay was 3.00 (3.00, 3.75) days, the postoperative SIS-6 score was (4.90±1.58) points at 3 months, and the postoperative VHI-10 score was 7.50 (2.00, 11.00) points at 3 months. Seven patients had mild mandibular numbness, 10 patients had mild cervical numbness, and 3 patients had temporary hypothyroidism three months after surgery and 1 patient had skin flap burn, but recovered one month after surgery. All patients were satisfied with the postoperative aesthetic effects, and the postoperative aesthetic VAS score was 10.00 (10.00, 10.00). Conclusion: Gasless transoral vestibular robotic thyroidectomy using skin suspension is a safe and feasible option with good postoperative aesthetic effect, which can provide a new treatment option for some selected patients with thyroid tumors.

[Endoscopic ultrasonographic features of submucosal lesions of upper digestive tract suspected gastrointestinal stromal tumors and their correlation with progression and pathological risk grade of the lesions]

Objective: To investigate the endoscopic ultrasonographic (EUS) characteristics of submucosal lesions of upper digestive tract suspected gastrointestinal stromal tumors (GIST) and their correlation with biological behaviors and pathological risk grade of the tumors. Methods: Retrospective cohort study. The EUS findings, follow-up review, surgical treatment and pathological data of patients with suspected GIST at the Gastrointestinal Endoscopy Center of Peking University People's Hospital from January 2013 to April 2021 were collected. All samples were divided into follow-up group and treatment group based on the pathological condition and the patient's treatment intention. According to whether or not the tumor was enlarged in EUS, the follow-up group was divided into non-enlarged group and enlarged group. Paired T-test was used to compare the lesion size before and after follow-up, and logistic regression was used to analyze the risk factors of tumor enlargement. According to the treatment methods, the treatment group was further divided into endoscopic treatment group and surgical treatment group. According to the pathological results and risk grade, the treatment group was further divided into the low-risk group and the medium-risk group. The risk factors of pathological malignant risk were analyzed by logistic regression, and the tumor diameter of patients with moderate or above pathological risk was predicted by receiver operation characteristic (ROC) curve. The relationship between the findings of EUS and the progression and pathological risk of GIST were also explored. Results: Seventy-three cases including 23 males and 50 females, with an age of 58 (30-88) years, were included in the follow-up group, with a mean lesion diameter of (1.21±0.49) cm before follow-up, median follow-up interval of 33.8 months, and a lesion diameter of (1.18±0.49) cm after follow-up. There was no significant difference (all P>0.05) in lesion diameter between before and after follow-up. There was no significant difference (all P>0.05) between tumor enlargement group (18 cases, 24.7%) and non-enlargement group (55 cases, 75.3%). One hundred and thirty-eight cases, including 52 males and 86 females, with an age of 60 (19-84) years, were enrolled in the treatment group, with a mean EUS estimated diameter of (2.55±1.35) cm and pathological diameters of (3.43±2.42) cm. Ninety-five (68.8%) of these cases were pathologically confirmed as GIST while 43 cases were diagnosed as other tumor types, including 37 benign tumors and 6 malignant tumors. In multifactorial logistic regression analysis, only the increase of tumor diameter [OR (95%CI): 1.800 (1.172-2.766), P=0.007] was a risk factor for pathological intermediate or higher risk. The optimal tumor diameter for predicting pathological intermediate or higher risk using ROC curve analysis was 2.75 cm, with a sensitivity 71.4%, specificity 79.0%, Youden index 0.5 and area under ROC curve 0.807 (95%CI: 0.703-0.909). Conclusions: EUS is essential for assessing the risk of progression and malignancy of submucosal lesions of upper digestive tract suspected GIST. For lesions of small diameter, the interval of follow-up shall be relatively extended while the indication of treatment could be partially waived.

[Transient elastography technology role assessment during the diagnosis and treatment of patients with chronic hepatitis B virus infection]

Objective: To explore the role of transient elastography technology in the assessment of disease staging and treatment in patients with chronic hepatitis B virus (HBV) infection. Methods: Patients who were clinically diagnosed with chronic HBV infection at Beijing Tsinghua Changgung Hospital from January 2018 to December 2021 was collected. Liver stiffness measurement (LSM) examination was performed more than once by transient elastography. The count data were expressed as cases (%) and the χ (2) test was made. Fisher's exact test was used with theoretical frequency less than 5. The measurement data between two groups was compared by t-test. Multiple groups were compared with an analysis of variance. Results: 1 055 patients were included in this study, including 669 (63.4%) males and 386 (36.6%) females. 757 (71.8%) patients were untreated. Among the untreated patients, the LSM value in the immune clearance (10.2 ± 3.8) kPa (187 cases, 40.4%), and the reactivation stages (9.1 ± 3.4) kPa (114 cases, 24.6%) was significantly higher than that in the immune tolerance (8.7 ± 3.6) kPa (78 cases, 16.8%) and immune control stages (8.4 ± 3.5) KPa (84 cases, 18.1%), and the difference between the four groups was statistically significant (F = 5.31 and P = 0.03). With ALT (male: 30 U/L, female: 19 U/L) as defined the normal value, the LSM value in the immune tolerance and the immune control stages were (5.8 ± 0.9) kPa and (7.1 ± 2.5) kPa, respectively, which were significantly lower than those of patients in the immune tolerance and immune control stages, and the difference was statistically significant (P < 0.01). There were 294 (38.8%) patients with uncertain period, excluding patients with fatty liver. Patients with uncertain periods were divided into four gray zone (GZ) groups: immune tolerance stage: LSM (5.1 ± 1.3) kPa was significantly lower than GZ-A (6.5 ± 2.4) kPa, t = 2.06, P = 0.03, and the difference was statistically significant; immune control stage: LSM was (5.6 ± 1.5) kPa, which was also lower than GZ-C (6.8 ± 1.3) kPa, t = 3.08, P = 0.02, and the difference was statistically significant; immune clearance stage: LSM > 8.0 kPa. LSM values showed a year-by-year reduction in patients with expanded indications who started antiviral treatment and were followed up for three years. Conclusion: The LSM value is significantly lower after the decrease of the defined high-normal ALT value in patients with the immune tolerance and immune control stages of chronic HBV infection. The LSM values of GZ-A and GZ-C in the uncertain periods of chronic HBV infection are higher than those of patients in the immune tolerance and immune control stages.

[Study on protective effects and mechanisms of total glucosides of Paeony on Graves disease in BALB/c mice]

Objective: To investigate the protective effect and its immunoregulatory mechanism of Total Glucosides of Paeony (TGP) against Graves' Disease (GD) model on BALB/c mice. Methods: Fifty female (6 weeks old, weighing 16-18 g) BALB/c mice of specific pathogen free were divided into control group according to random number table method, model group, early low-dose TGP intervention group (250 mg·kg^-1·d^-1), early high-dose TGP intervention group (500 mg·kg^-1·d^-1), and late TGP intervention group, with 10 mice in each group. Except the control group, the other 4 groups were immunized 3 times (0, 3^rd, and 6^th week) with recombinant adenovirus expressing the thyroid stimulating hormone receptor (TSHR) A subunit to establish the GD model. The early low-dose and high-dose intervention group were given diets containing different doses of TGP throughout the whole process, and the late intervention group was given diets containing low doses of TGP from the 1^st week after the 2^nd immunization (week 4). The levels of thyrotropin receptor antibody (TRAb) and total thyroxine (TT4) were detected in the tail venous blood of mice at the 4^th week. At the 10^th week, the serum TRAb and TT4 levels and the ratio of regulatory T cells (Treg) in each group were detected, and the pathological changes of thyroid tissue were observed. Serum helper T cell 1(Th1) and Th2 cell-related factors interleukin-2 (IL-2), IL-4, IL-5, IL-10, IL-12p70, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-γ (IFN-γ) and tumor necrosis factors-α (TNF-α) were detected to investigate the protective effect of TGP on GD model in BALB/c mice and its mechanism. Results: At the 4^th week, The level of TT4 [(55.07±12.89) μg/L] in early high-dose intervention group was lower than that in model group [(74.33±8.63) μg/L] (all P<0.05). The level of TT4 in early low-dose intervention group and late intervention group and model group had no statistical significance (all P>0.05). TRAb level of mice between early low-dose, early high-dose, late intervention groups and model group was no significant difference (all P>0.05). At the 10^th week, TRAb [(90.00±26.89) U/L] and TT4[(32.66±8.11) μg/L] levels in the early high-dose intervention group were lower than those in the model group [(396.97±95.35) U/L, (73.70±16.33) μg/L] (all P<0.05). The TRAb and TT4 levels in the early low-dose intervention group and late intervention group were not significantly different from those in the model group (all P>0.05). The thyroid tissue of hyperthyroidism mice in the early high dose intervention group showed focal hypertrophic changes, while the thyroid tissue of other hyperthyroidism mice showed diffuse hypertrophic changes. The CD4⁺CD25⁺/CD4⁺Treg ratio in early high-dose intervention group was higher than that in model group at the 10^th week (4 weeks after three recombinant adenovirus immunization) (P<0.05). Compared with the model group at the 10^th week, the levels of IL-2, IL-12p70 and IFN-γ in the early high-dose intervention group were all decreased (all P<0.05), and the levels of IL-10 were increased (P<0.05). Conclusion: Early high-dose (500 mg·kg^-1·d^-1) TGP intervention group displays a protective effect against GD mice, the mechanism of which may be related to regulatory T cell function changes and Th1/Th2 cytokine balance restoration.

The Arabidopsis D27-LIKE1 is a cis/cis/trans-β-carotene isomerase that contributes to Strigolactone biosynthesis and negatively impacts ABA level

The enzyme DWARF27 (D27) catalyzes the reversible isomerization of all-trans- into 9-cis-β-carotene, initiating strigolactone (SL) biosynthesis. Genomes of higher plants encode two D27-homologs, D27-like1 and -like2, with unknown functions. Here, we investigated the enzymatic activity and biological function of the Arabidopsis D27-like1. In vitro enzymatic assays and expression in Synechocystis sp. PCC6803 revealed an unreported 13-cis/15-cis/9-cis- and a 9-cis/all-trans-β-carotene isomerization. Although disruption of AtD27-like1 did not cause SL deficiency phenotypes, overexpression of AtD27-like1 in the d27 mutant restored the more-branching phenotype, indicating a contribution of AtD27-like1 to SL biosynthesis. Accordingly, generated d27 d27like1 double mutants showed a more pronounced branching phenotype compared to d27. The contribution of AtD27-like1 to SL biosynthesis is likely a result of its formation of 9-cis-β-carotene that was present at higher levels in AtD27-like1 overexpressing lines. By contrast, AtD27-like1 expression correlated negatively with the content of 9-cis-violaxanthin, a precursor of ABA, in shoots. Consistently, ABA levels were higher in shoots and also in dry seeds of the d27like1 and d27 d27like1 mutants. Transgenic lines expressing GUS driven by the AtD27LIKE1 promoter and transcript analysis of hormone-treated Arabidopsis seedlings revealed that AtD27LIKE1 is expressed in different tissues and affects ABA and auxin. Taken together, our work reports a cis/cis-β-carotene isomerase that affects the content of both cis-carotenoid-derived plant hormones, ABA and SLs.

ZAXINONE SYNTHASE 2 regulates growth and arbuscular mycorrhizal symbiosis in rice

Carotenoid cleavage, catalyzed by CAROTENOID CLEAVAGE DIOXYGENASEs (CCDs), provides signaling molecules and precursors of plant hormones. Recently, we showed that zaxinone, a apocarotenoid metabolite formed by the CCD ZAXINONE SYNTHASE (ZAS), is a growth regulator required for normal rice (Oryza sativa) growth and development. The rice genome encodes three OsZAS homologs, called here OsZAS1b, OsZAS1c, and OsZAS2, with unknown functions. Here, we investigated the enzymatic activity, expression pattern, and subcellular localization of OsZAS2 and generated and characterized loss-of-function CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats and associated protein 9)-Oszas2 mutants. We show that OsZAS2 formed zaxinone in vitro. OsZAS2 was predominantly localized in plastids and mainly expressed under phosphate starvation. Moreover, OsZAS2 expression increased during mycorrhization, specifically in arbuscule-containing cells. Oszas2 mutants contained lower zaxinone content in roots and exhibited reduced root and shoot biomass, fewer tillers, and higher strigolactone (SL) levels. Exogenous zaxinone application repressed SL biosynthesis and partially rescued the growth retardation of the Oszas2 mutant. Consistent with the OsZAS2 expression pattern, Oszas2 mutants displayed a lower frequency of arbuscular mycorrhizal colonization. In conclusion, OsZAS2 is a zaxinone-forming enzyme that, similar to the previously reported OsZAS, determines rice growth, architecture, and SL content, and is required for optimal mycorrhization.

Metabolomics of plant root exudates: From sample preparation to data analysis

Plants release a set of chemical compounds, called exudates, into the rhizosphere, under normal conditions and in response to environmental stimuli and surrounding soil organisms. Plant root exudates play indispensable roles in inhibiting the growth of harmful microorganisms, while also promoting the growth of beneficial microbes and attracting symbiotic partners. Root exudates contain a complex array of primary and specialized metabolites. Some of these chemicals are only found in certain plant species for shaping the microbial community in the rhizosphere. Comprehensive understanding of plant root exudates has numerous applications from basic sciences to enhancing crop yield, production of stress-tolerant crops, and phytoremediation. This review summarizes the metabolomics workflow for determining the composition of root exudates, from sample preparation to data acquisition and analysis. We also discuss recent advances in the existing analytical methods and future perspectives of metabolite analysis.

[Implement of mixed reality navigation based on multimodal imaging in the resection of intracranial eloquent lesions]

Objective: To examine the clinical feasibility of mixed reality navigation (MRN) technology based on multimodal imaging for the resection of intracranial eloquent lesions. Methods: Fifteen patients with intracranial eloquent lesions admitted to the Department of Neurosurgery, the First Medical Center, People's Liberation Army General Hospital from September 2020 to September 2021 were retrospectively enrolled. There were 7 males and 8 females, aged (50±16) years (range: 16 to 70 years). Postoperative pathological diagnosis included meningioma (n=7), metastatic carcinoma (n=3), cavernous hemangioma, glioma, ependymoma, aneurysmal changes and lymphoma (n=1, respectively). The open-source software was used to perform the three-dimensional visualization of preoperative images, and the self-developed MRN system was used to perform the fusion and interaction of multimodal images, so as to formulate the surgical plan and avoid damaging the eloquent white matter fiber tracts. Traditional navigation, intraoperative ultrasound and fluorescein sodium angiography were used to determine the extent of lesion resection. The intraoperative conditions of MRN-assisted surgery were analyzed, and the setup time and localization error of MRN system were measured. The changes of postoperative neurological function were recorded. Results: MRN based on multimodal imaging was achieved in all patients. The MRN system setup time (M(IQR)) was 36 (12) minutes (range: 20 to 44 minutes), and the localization error was 3.2 (2.0) mm (range: 2.6 to 6.7 mm). The reliability of eloquent white matter fiber tracts localization based on MRN was rated as "excellent" in 11 cases, "medium" in 3 cases, and "poor" in 1 case. There were no perioperative death and no new impairment in motor, language, or visual functions after operation. Transient limb numbness occurred in 1 patient after operation, and recovered to the preoperative state in 2 weeks after operation. Conclusion: The MRN system based on multimodal imaging can improve the surgical accuracy and safety, and reduce the incidence of iatrogenic neurological dysfunction.

Perspectives on the metabolism of strigolactone rhizospheric signals

Strigolactones (SLs) are a plant hormone regulating different processes in plant development and adjusting plant's architecture to nutrition availability. Moreover, SLs are released by plants to communicate with beneficial fungi in the rhizosphere where they are, however, abused as chemical cues inducing seed germination of root parasitic weeds, e.g. Striga spp., and guiding them towards host plants in their vicinity. Based on their structure, SLs are divided into canonical and non-canonical SLs. In this perspective, we describe the metabolism of root-released SLs and SL pattern in rice max1-900 mutants, which are affected in the biosynthesis of canonical SLs, and show the accumulation of two putative non-canonical SLs, CL+30 and CL+14. Using max1-900 and SL-deficient d17 rice mutants, we further investigated the metabolism of non-canonical SLs and their possible biological roles. Our results show that the presence and further metabolism of canonical and non-canonical SLs are particularly important for their role in rhizospheric interactions, such as that with root parasitic plants. Hence, we proposed that the root-released SLs are mainly responsible for rhizospheric communications and have low impact on plant architecture, which makes targeted manipulation of root-released SLs an option for rhizospheric engineering.

Canonical strigolactones are not the major determinant of tillering but important rhizospheric signals in rice

Strigolactones (SLs) are a plant hormone inhibiting shoot branching/tillering and a rhizospheric, chemical signal that triggers seed germination of the noxious root parasitic plant Striga and mediates symbiosis with beneficial arbuscular mycorrhizal fungi. Identifying specific roles of canonical and noncanonical SLs, the two SL subfamilies, is important for developing Striga-resistant cereals and for engineering plant architecture. Here, we report that rice mutants lacking canonical SLs do not show the shoot phenotypes known for SL-deficient plants, exhibiting only a delay in establishing arbuscular mycorrhizal symbiosis, but release exudates with a significantly decreased Striga seed-germinating activity. Blocking the biosynthesis of canonical SLs by TIS108, a specific enzyme inhibitor, significantly lowered Striga infestation without affecting rice growth. These results indicate that canonical SLs are not the determinant of shoot architecture and pave the way for increasing crop resistance by gene editing or chemical treatment.

9-cis-β-Apo-10'-carotenal is the precursor of strigolactones in planta

¹³C-isotope feeding experiments demonstrate that the apocarotenoid 9-cis-β-apo-10'-carotenal is the precursor of several strigolactones in rice, providing a direct, in planta evidence for its role in strigolactone biosynthesis. Strigolactones (SLs) are plant hormone that regulates plant architecture and mediates rhizospheric communications. Previous in vitro studies using heterogously produced enzymes unraveled the conversion of all-trans-β-carotene via the intermediate 9-cis-β-apo-10'-carotenal into the SL precursor carlactone. However, a direct evidence for the formation of SLs from 9-cis-β-apo-10'-carotenal is still missing. To provide this evidence, we supplied rice seedlings with ¹³C-labeled 9-cis-β-apo-10'-carotenal and analyzed their SLs by LC-MS. Our results show that 9-cis-β-apo-10'-carotenal is the SL precursor in planta and reveal, for the first time, the application of labeled long-chain apocarotenoids as a promising approach to investigate apocarotenoid metabolism and the genesis of carotenoid-derived growth regulators and signaling molecules.

[Preliminary experience of robotic lateral neck dissection via combined axillary-retroauricular approach for N1b papillary thyroid carcinoma]

Objective: To evaluate the feasibility, safety, and short-term efficacy of robotic lateral neck dissection via combined axillary-retroauricular approach for N1b papillary thyroid carcinoma (PTC). Methods: Thirty patients with cT1-2N1bM0 PTC who received robotic lateral neck dissection via combined axillary-retroauricular approach were included in the Department of Otorhinolaryngology of Sun Yat-sen Memorial Hospital from December 2016 to December 2020. There were 10 males and 20 females, with a median age of 34.5 years and a median body mass index of 25.55 kg/m². The clinical, surgical, complications, pathology and follow-up data were analysed with SPSS 25.0 software package. Results: The median operative time of 30 patients was 255.50 min, the median operative blood loss was 69.00 ml, and the median postoperative hospital stay was 6.00 days. The incidence of postoperative temporary recurrent laryngeal nerve paralysis was 3.33% (1/30), temporary hypoparathyroidism was 16.67%(5/30), temporary accessory nerve injury was 3.33% (1/30), hematoma was 3.33% (1/30) and chylous leakage was 3.33% (1/30). The median visual analogue scale (VAS) score was 8.00, and the follow-up time was 13-38 months, with a median of 25.5 months. One case showed cervical lymph node recurrence 14 months after surgery. The most recent dynamic recurrence risk stratification showed 21 patients (70.00%) had excellent responses. Conclusions: Robotic lateral neck dissection via combined axillary-retroauricular approach for unilateral cN1b PTC is safe, feasible and aesthetic. The short-term efficacy and dynamic recurrence risk stratification results of short-term follow-up are satisfactory. It can provide a surgical option for cN1b PTC patients.

Zaxinone synthase controls arbuscular mycorrhizal colonization level in rice

The Oryza sativa (rice) carotenoid cleavage dioxygenase OsZAS was described to produce zaxinone, a plant growth-promoting apocarotenoid. A zas mutant line showed reduced arbuscular mycorrhizal (AM) colonization, but the mechanisms underlying this behavior are unknown. Here, we investigated how OsZAS and exogenous zaxinone treatment regulate mycorrhization. Micromolar exogenous supply of zaxinone rescued root growth but not the mycorrhizal defects of the zas mutant, and even reduced mycorrhization in wild-type and zas genotypes. The zas line did not display the increase in the level of strigolactones (SLs) that was observed in wild-type plants at 7 days post-inoculation with AM fungus. Moreover, exogenous treatment with the synthetic SL analog GR24 rescued the zas mutant mycorrhizal phenotype, indicating that the lower AM colonization rate of zas is caused by a deficiency in SLs at the early stages of the interaction, and indicating that during this phase OsZAS activity is required to induce SL production, possibly mediated by the Dwarf14-Like (D14L) signaling pathway. OsZAS is expressed in arbuscule-containing cells, and OsPT11prom::OsZAS transgenic lines, where OsZAS expression is driven by the OsPT11 promoter active in arbusculated cells, exhibit increased mycorrhization compared with the wild type. Overall, our results show that the genetic manipulation of OsZAS activity in planta leads to a different effect on AM symbiosis from that of exogenous zaxinone treatment, and demonstrate that OsZAS influences the extent of AM colonization, acting as a component of a regulatory network that involves SLs.

Protocol for characterizing strigolactones released by plant roots

The plant hormone strigolactones (SLs) are secreted by plant roots to act as rhizospheric signals. Here, we present a protocol for characterizing plant-released SLs. We first outline all necessary steps required for collection, processing, and analysis of plant root exudates using the C18 column for SL extraction, followed by liquid chromatography-mass spectrometry (LC-MS) for SL quantification. We then describe image processing by SeedQuant, an open-source artificial-intelligence-based software, for measuring the biological activity of SLs in inducing root parasitic plant seed germination. For complete details on the use and execution of this protocol, please refer to Wang et al. (2019) and Braguy et al. (2021).