Rapid detection of furanyl fentanyl in complex matrices using Leidenfrost desorption-assisted low-temperature arc plasma ionization mass spectrometry

The abuse of illicit drugs poses serious threats to the physical and mental health of users, as well as to the overall safety and welfare of society. In this work, we present a newly developed technique for drug detection based on mass spectrometry. This technique combines Leidenfrost desorption with low-temperature arc plasma ionization mass spectrometry. This method is applicable for detecting furanyl fentanyl in complex matrices. Key advantages of this technique include minimal sample fragmentation and high sensitivity for detection. The Leidenfrost desorption plays a pivotal role in this methodology, as it spontaneously concentrates analyte molecules during the gradual evaporation of the solvent. Eventually, these concentrated molecules are redistributed at their highest concentrations, resulting in exceptionally high sensitivity. In the course of our investigation, we achieved a remarkable detection limit of 10 pg mL-1 for furanyl fentanyl in pure water. Moreover, the characteristic ion peaks of furanyl fentanyl can be distinctly identified within complex matrices such as wine, beverages, urine, and lake water. This innovative drug detection technology offers several advantages, including a simple setup, cost-effectiveness, rapid detection, high sensitivity, and minimal sample pretreatment.

[Propensity score matching analysis of the short-term efficacy of Kamikawa versus double- tract reconstruction in laparoscopic proximal gastric cancer surgery]

Objective: To compare the short-term efficacy of Kamikawa anastomosis and double-tract reconstruction (DTR) after proximal gastrectomy. Methods: This was a propensity score matched, retrospective, cohort study. Inclusion criteria comprised age 20-70 years, diagnosis of gastric cancer by pathological examination of preoperative endoscopic biopsies, tumor diameter ≤4 cm, and location in the upper 1/3 of the stomach (including the gastroesophageal junction), and TNM stage IA, IB, or IIA. The study cohort comprised 73 patients who had undergone laparoscopic proximal gastric cancer radical surgery in the Department of Gastroenterology, Tangdu Hospital, Air Force Medical University between June 2020 and February 2023, 19 of whom were in the Kamikawa group and 54 in the DTR group. After using R language to match the baseline characteristics of patients in a ratio of 1:2, there were 17 patients in the Kamikawa group and 34 in the DTR group. Surgery-related conditions, postoperative quality of life, and postoperative complications were compared between the two groups. Results: After propensity score matching, there were no statistically significant differences in baseline data between the two groups (P>0.05). Compared with the DTR group, the Kamikawa group had longer operative times (321.5±15.7 minutes vs. 296.8±26.1 minutes, t=32.056, P<0.001), longer anastomosis times (93.0±6.8 minutes vs. 45.3±7.7 minutes, t=56.303, P<0.001), and less bleeding (76 [54~103] mL vs.112 [82~148) mL, Z=71.536, P<0.001); these differences are statistically significant. There were no statistically significant differences between the two groups in tumor size, time to first postoperative passage of gas, postoperative hospital stay, number of lymph nodes removed, duration of lymph node dissection, or total hospitalization cost (all P>0.05). The median follow-up time was 6.1 ± 1.8 months. As to postoperative quality of life, the Kamikawa group had a lower rate of upper gastrointestinal contrast reflux than did the DTR group (0 vs. 29.4% [10/34], χ2=6.220, P=0.013); this difference is statistically significant. However, differences between the two groups in quality of life score on follow-up of 3 months and 6 months on the Gastroesophageal Reflux Disease (GERD) scale were not statistically significant (all P>0.05). The incidence of postoperative complications was 2/17 in the Kamikawa group, which is significantly lower than the 41.2% (14/34) in the DTR group (χ2=4.554, P=0.033). Conclusion: Kamikawa anastomosis and DTR are equally safe and effective procedures for reconstructing the digestive tract after proximal gastric surgery. Although Kamikawa anastomosis takes slightly longer and places higher demands on the surgical team, it is more effective at preventing postoperative reflux.

Prevalence and influencing factors of depressive and anxiety symptoms among hospital-based healthcare workers during the surge period of the COVID-19 pandemic in the Chinese mainland: a multicenter cross-sectional study

BACKGROUND

From November 2022 to February 2023, the Chinese mainland experienced a surge in COVID-19 infection and hospitalization, and the hospital-based healthcare workers (HCWs) might suffer serious psychological crisis during this period. This study aims to assess the depressive and anxiety symptoms among HCWs during the surge of COVID-19 pandemic and to provide possible reference on protecting mental health of HCWs in future infectious disease outbreaks.

METHODS

A multicenter cross-sectional study was carried out among hospital-based HCWs in the Chinese mainland from 5 January to 9 February 2023. The PHQ-9 (nine-item Patient Health Questionnaire) and GAD-7 (seven-item Generalized Anxiety Disorder Questionnaire) were used to measure depressive and anxiety symptoms. Ordinal logistic regression analysis was performed to identify influencing factors.

RESULTS

A total of 6522 hospital-based HCWs in the Chinse mainland were included in this survey. The prevalence of depressive symptoms among the HCWs was 70.75%, and anxiety symptoms was 47.87%. The HCWs who perceived higher risk of COVID-19 infection and those who had higher work intensity were more likely to experience depressive and anxiety symptoms. Additionally, higher levels of mindfulness, resilience and perceived social support were negatively associated with depressive and anxiety symptoms.

CONCLUSION

This study revealed that a high proportion of HCWs in the Chinese mainland suffered from mental health disturbances during the surge of the COVID-19 pandemic. Resilience, mindfulness and perceived social support are important protective factors of HCWs' mental health. Tailored interventions, such as mindfulness practice, should be implemented to alleviate psychological symptoms of HCWs during the COVID-19 pandemic or other similar events in the future.

Probing Acid-Induced Compaction of Denatured Proteins by High-Pressure Electrospray Mass Spectrometry

Further increase in the acidity in the most denaturing acidic solution is known to induce compaction of the fully unfolded protein into a compact molten globule. The phenomenon of "acid-induced folding of proteins" takes place at pH ∼1 in strong acid aqueous solutions with high electrical conductivity and surface tension, a condition that is difficult to handle using conventional electrospray ionization methods for mass spectrometry. Here, high-pressure electrospray ionization (HP-ESI) is used to produce well-resolved mass spectra for proteins in strong acids with pH as low as 1. The compaction of protein conformation is indicated by a large shift in the charge state from high charges to native-like low charges. The addition of salt to the protein in the most denaturing condition also reproduces the compaction effect, thereby supporting the role of anions in this phenomenon. Similar compaction of proteins is also observed in organic solvent/acid mixtures. The charge state of the compacted protein depends on the type of anions that formed ion pairs with a positive charge on the protein. The dissociation of ion pairs during the ionization process forms neutral acids that can be observed by HP-ESI using a soft ion introduction configuration.

Effect of Segmental Abutting Esophagus-Sparing Technique to Reduce Severe Esophagitis in Limited-Stage Small-Cell Lung Cancer Patients Treated with Concurrent Hypofractionated Thoracic Radiation and Chemotherapy

PURPOSE/OBJECTIVE(S)

To evaluate the effect of segmental abutting esophagus-sparing (SAES) radiotherapy to reduce severe (G3+) acute esophagitis from 20% to 5% in patients with limited-stage small cell lung cancer (LS-SCLC) treated with concurrent chemoradiotherapy.

MATERIALS/METHODS

Patients with a clinical target volume (CTV) ≤1 cm close to the esophagus were enrolled in the experimental arm (45 Gy in 3 Gy daily fractions in 3 weeks) of an ongoing phase III randomized clinical trial (NCT02675088), which enrolled patients with histologically confirmed SCLC and clinically staged as LS or I-IIIB (AJCC 7th). This trial was designed to determine whether HYPO TRT (45 Gy in 3 Gy QD, experimental arm) has the same efficacy as CF TRT (60 Gy in 2 Gy QD, controlled arm) in patients with LS-SCLC. The whole esophagus was divided into the involved esophagus and abutting esophagus (AE) to receive different dose limitations according to the distance from the edge of the CTV. The primary endpoint was grade ≥ 3 acute esophagitis.

RESULTS

From 1 May 2021 to 30 April 2022, 30 patients were enrolled and completed four cycles of planned chemotherapy and radiotherapy. Our patient population was predominantly male (66.7% men vs. 33.3% women), with a median age of 62 years. A majority of patients presented with Stage N2-3 (90.0%) and T2-4 (76.7%), in which 4 patients had ultracentral-located primary tumors. With the SAES technique, all dosimetric parameters were significantly reduced for the whole esophagus and AE. The maximal and mean dose of the esophagus (47.4±1.9 Gy and 13.5 ± 5.8 Gy, respectively) and AE (42.9±2.3 Gy and 8.6 ± 3.6 Gy, respectively) in the SAES plan were significantly lower than those (esophagus 48.0±1.9 Gy and 14.7± 6.1 Gy, AE 45.1±2.4 Gy and 9.8± 4.2 Gy, respectively) in the non-SAES plan. After the follow-up of more than 7 months (range, 7.0-18.1 months) for all patients, only one patient (3.3%, 95% CI 0.1%-17.2%) experienced grade 3 acute esophagitis and no grade 4-5 acute esophagitis happened (Table 3). For late toxicities, one patient suffered sustained grade 1 late esophagitis and all others had no symptoms of esophagitis. The rate of radiation pneumonitis was very low, with one grade 3 event and no grade 4-5 event. Twelve (40.0%) patients had G3+ hematologic toxic events, including 2 patients with febrile neutropenia. The 1-year OS, LRFS, DMFS and PFS was 96.4%, 88.7%, 78.4% and 64.3%, respectively. No patient developed local recurrence in the abutting esophagus-sparing region.

CONCLUSION

SAES radiotherapy has significant dosimetric advantages compared with standard radiotherapy, which are successfully translated into clinical benefits for patients with LS-SCLC treated with 45 Gy in 3 Gy daily fractions. This may facilitate dose escalation for TRT in LS-SCLC patients.

Feedback Control of Electrospray with and without an External Liquid Pump Using the Spray Current and the Apex Angle of a Taylor Cone for ESI-MS

An electrospray operated in the steady cone-jet mode is highly stable but the operating state can shift to pulsation or multijet modes owing to changes in flow rate, surface tension, and electrostatic variables. Here, a simple feedback control system was developed using the spray current and the apex angle of a Taylor cone to determine the error signal for correcting the emitter voltage. The system was applied to lock the cone-jet mode operation against external perturbations. For a pump-driven electrospray at a regulated flow rate, the apex angle of the Taylor cone decreased with increasing voltage. In contrast, for a voltage-driven electrospray with low flow resistance, the angle was found to increase with the emitter voltage. A simple algorithm based on iterative learning control was formulated and implemented using a personal computer to automatically correct the emitter voltage in response to the error signal. For voltage-driven electrospray ionization (ESI), the feedback control of the spray current can also be used to regulate the flow rate to an arbitrary value or pattern. Electrospray ionization-mass spectrometry (ESI-MS) with feedback control was demonstrated to produce ion signal acquisition with long-term stability that was insusceptible to the emulated external disturbances.

[Establishment of hysteroscopic scoring system of chronic endometritis and correlative analysis with pregnancy outcomes of in vitro fertilization-embryo transfer in infertile patients]

Objective: To establish a hysteroscopic chronic endometritis (hCE) scoring system for patients with chronic endometritis, and observe the correlation of hCE score with in vitro fertilization-embryo transfer (IVF-ET) pregnancy outcomes in infertile women. Methods: The study retrospectively investigated the correlation of morphologic features and hCE score with pregnancy outcomes during IVF-ET in infertile women with CE (n=429) at Yantai Yuhuangding Hospital between January 2017 and September 2018. The clinical pregnancy rate and live birth rate with different score levels (1-3,4-7 and 8-14) after IVF-ET treatment were analyzed. Multivariate regression analysis was performed to adjust for confounding factors. The correlation and regression between hCE score and pregnancy outcomes was analyzed by curve fitting. Results: The age of 429 patients [M(Q₁, Q₃)] was 31 (29, 35) years. There were 50.6% (217 cases), 35.4% (152 cases), and 14.0% (60 cases) of patients with hCE score of 1-3, 4-7, and 8-14, respectively. The pregnancy rates of the three groups were 60.8% (132 cases), 44.7% (68 cases) and 16.7% (10 cases), P<0.001; The live birth rates were 51.2% (111 cases), 36.8% (56 cases) and 13.3% (8 cases), respectively (P<0.001). Compared with patients with hCE of 1-3, pregnancy rates in those with hCE of 4-7 and 8-14 were lower, and the OR values were 0.521 (0.342-0.793) and 0.129 (0.062-0.268). The live birth rates in patients with hCE of 4-7 and 8-14 were lower than that in patients with hCE of 1-3, and the OR values were 0.570 (0.372-0.873) and 0.162 (0.073-0.360), all P<0.05. Quadratic curve fitting results showed that clinical pregnancy rate and live birth rate decreased with the increase of hCE score. Conclusions: With the increase of hCE score, the clinical pregnancy rate and live birth rate of patients gradually decrease. hCE 4 is an important cut-off threshold significantly affecting the pregnancy outcome.

Tuning oxidative modification by a strong electric field using nanoESI of highly conductive solutions near the minimum flow rate

Oxidative modification is usually used in mass spectrometry (MS) for labeling and structural analysis. Here we report a highly tunable oxidation that can be performed in line with the nanoESI-MS analysis at the same ESI emitter without the use of oxidative reagents such as ozone and H₂O₂, and UV activation. The method is based on the high-pressure nanoESI of a highly conductive (conductivity >3.8 S m^-1) aqueous solution near the minimum flow rate. The ion source is operated under super-atmospheric pressure (0.5 MPa gauge pressure) to avoid the contribution of electric discharge. The analyte at the tip of the Taylor cone or in the emitter droplet can be locally oxidized in an on-demand manner by varying the nanoflow rate. With an offline nanoESI, the degree of oxidation, i.e., the average number of incorporated oxygen atoms, can be finely tuned by voltage modulation using spray current as the feedback signal. Oxidations of easily oxidized residues present in peptides/proteins and the double bonds of the unsaturated phosphatidylcholine occur at low flow rate operation (<5 nL min^-1) when the electric field at the tip of the Taylor cone and the initially produced charged droplet reaches approximately 1.3 V nm^-1. The oxidized ion signal responds instantaneously to changes in flow rate, indicating that the oxidation is highly localized. Using isotope labeling, it was found that the incorporated oxygen primarily originates from the gas phase, suggesting a direct oxidation pathway for the analyte enriched on the liquid surface via the reactive oxygen atoms formed by the strong electric field.

Bipolar Electrospray from Electrodeless Emitters for ESI without Electrochemical Reactions in the Sprayer

A bipolar ESI source is developed to generate a simultaneous emission of charged liquid jets of opposite polarity from an electrodeless sprayer. The sprayer consists of two emitters, and the electrosprays are initiated by applying a high potential difference (HV) across the counter electrodes facing each emitter. The sprayer and the liquid delivery system are made of all insulators without metal components, thus enabling the total elimination of electrochemical reactions taking place at the liquid-electrode interface in the typical electrosprayer. The bipolar electrospray has been implemented using an online configuration that uses a syringe pump for flow rate regulation and an offline configuration that relies on HV for adjusting the flow rate. The voltage-current and flow rate-current relationships of bipolar electrospray were found to be similar to the standard electrospray. The application of bipolar ESI to the mass spectrometry of protein, peptide, and metallocene without electrochemically induced oxidation/reduction is demonstrated.

Aneurysmal bone cyst of the temporal bone presenting with reversible vestibular impairment

BACKGROUND

Aneurysmal bone cysts are expansile benign lesions associated with compressive destruction and obscure pathogenesis. The most common sites of temporal bone involvement are the petrous apex, squamous portions and mastoid.

CASE REPORT

This paper reports a right temporal aneurysmal bone cyst in a 51-year-old man who presented clinically with facial palsy, and hearing loss and impaired vestibular function. Magnetic resonance imaging and computed tomography findings were consistent with a diagnosis of aneurysmal bone cyst. Inter-operative findings showed that the lesion had caused compressive damage to the internal auditory canal. Following surgical excision, the patient experienced vertigo, indicating recovery of vestibular function. Follow-up imaging revealed complete resection without clinical recurrence.

CONCLUSION

To our knowledge, this is the first report of aneurysmal bone cyst invasion of the inner auditory canal. Our clinical experience indicates that vestibular nerve damage recovery is relatively uncommon. This case report will hopefully inform future studies.

Foliar application of nanoceria attenuated cadmium stress in okra (Abelmoschus esculentus L.)

Foliar application of nanoparticles (NPs) as a means for ameliorating abiotic stress is increasingly employed in crop production. In this study, the potential of CeO₂-NPs as stress suppressants for cadmium (Cd)-stressed okra (Abelmoschus esculentus) plants was investigated, using two cycles of foliar application of CeO₂-NPs at 200, 400, and 600 mg/l. Compared to untreated stressed plants, Cd-stressed plants treated with CeO₂-NPs presented higher pigments (chlorophyll a and carotenoids). In contrast, foliar applications did not alter Cd root uptake and leaf bioaccumulation. Foliar CeO₂-NPs application modulated stress enzymes (APX, SOD, and GPx) in both roots and leaves of Cd-stressed plants, and led to decreases in Cd toxicity in plant's tissues. In addition, foliar application of CeO₂-NPs in Cd-stressed okra plants decreased fruit Cd contents, and improved fruit mineral elements and bioactive compounds. The infrared spectroscopic analysis of fruit tissues showed that foliar-applied CeO₂-NPs treatments did not induce chemical changes but induced conformational changes in fruit macromolecules. Additionally, CeO₂-NPs applications did not alter the eating quality indicator (Mg/K ratio) of okra fruits. Conclusively, the present study demonstrated that foliar application of CeO₂-NPs has the potential to ameliorate Cd toxicity in tissues and improve fruits of okra plants.

Expression of GMFB in High-Grade Cervical Intraepithelial Neoplasia and Its Role in Cervical Cancer

Cervical intraepithelial neoplasia (CIN) is a collective term for specific precancerous lesions associated with cervical cancer (CC). Although it has been affirmed with slow development of several levels of cellular changes, the existing poor prognosis calls for an urgent need to diagnose CIN at early stage and be aware of markers related to its pathogenesis and prognosis. We explored the expression level of a newly marker GMFB and its regulatory effect on CIN and CC. Patient samples and cell models were included. Bioinformatic studies were taken to predict its binding to miR-143-3p, miR-26b-5p, miR-191-5p, and miR-223-3p. Luciferase reporter and RNA pull-down assays were used to validate the prediction. Edu assay and flow cytometry were used to measure the regulation of GMFB on proliferation and apoptosis of CC cells. qRT-PCR was used for mRNA expression level detection. The results showed that GMFB was targeted by miR-143-3p, miR-26b-5p, miR-191-5p, and miR-223-3p. It had elevated expression in both CIN and CC samples. GMFB had highly prognostic value for CIN, and lymph node metastasis of CC was much associated with high GMFB expression level. Besides, silencing of GMFB inhibited CC cell proliferation and elevated cell apoptosis. In conclusion, we determined that GMFB has regulatory effect on high grade CIN and CC, which could lighten a novel way in exploring their pathogenesis and improving accuracy of prognosis.

Supplemented phase diagrams for vitrification CPA cocktails: DP6, VS55 and M22

DP6, VS55 and M22 are the most commonly used cryoprotective agent (CPA) cocktails for vitrification experiments in tissues and organs. However, complete phase diagrams for the three CPAs are often unavailable or incomplete (only available for full strength CPAs) thereby hampering optimization of vitrification and rewarming procedures. In this paper, we used differential scanning calorimetry (DSC) to measure the transition temperatures including heterogeneous nucleation temperatures (T_het), glass transition temperatures (T_g), rewarming phase crystallization (devitrification and/or recrystallization) temperatures (T_d) and melting temperatures (T_m) while cooling or warming the CPA sample at 5 °C/min and plotted the obtained transition temperatures for different concentrations of CPAs into the phase diagrams. We also used cryomicroscopy cooling or warming the sample at the same rate to record the ice crystallization during the whole process, and we presented the cryomicroscopic images at the transition temperatures, which agreed with the DSC presented phenomena.

Generation of Ions from Aqueous Taylor Cones near the Minimum Flow Rate: "True Nanoelectrospray" without Narrow Capillary

Generating ultrafine charged droplets using electrospray is crucial for attaining high ionization efficiency for mass spectrometry. The size of the precursor charged droplets depends on the spray flow rate, and conventional wisdom holds that an electrospray of a nL/min flow rate (nanoelectrospray) is only possible using narrow capillaries with an inner diameter of ∼1 μm or smaller. Here, the electrospray of aqueous solutions with high electric conductivities generated from a large off-line capillary of 0.4 mm i.d. has been performed using a high-pressure ion source. The electric discharge is avoided by operating the ion source at 2.5 bar gauge pressure. The highly stable Taylor cone can be tuned to a near-hydrostatic state that exhibits the "true nanoelectrospray" properties, i.e., high salt tolerance and minimal ion suppression. The Q^1/2 scaling law describing the electrospray current I and flow rate Q is found to be valid down to the nanoflow regime under a condition that is free of electric discharge. For a given solution, the flow rate and the size of the initial droplets and ionization species can be controlled with the spray current as the indicator for the instantaneous flow rate without changing the emitter capillary of different sizes. In regard to the application, the nanoelectrospray with a large micropipette tip is easy to use, free of clogging when dealing with viscous and high-salt buffer solutions, and with reduced surface interaction with the emitter inner surface. An acquisition of very clean mass spectra of proteins from concentrated solutions of nonvolatile salts such as phosphate-buffered saline is demonstrated.

[Japan narrow-band imaging Expert Team type 2B colorectal cancer: consistency between endoscopic prediction and pathological diagnosis]

OBJECTIVE

To explore the potential factors that affect the accuracy of endoscopic diagnosis for Japan narrow-band imaging (NBI) Expert Team (JNET) type 2B colorectal lesions.

OBJECTIVE

The clinical data were collected from 261 patients with JNET type 2B colorectal lesions diagnosed in Nanfang Hospital between July, 2018 and July, 2021. We analyzed the macroscopic type, size, location or pit pattern classification of the lesions for their potential influence of the diagnostic accuracy of JNET type 2B lesions.

OBJECTIVE

The 261 lesions included 91 low-grade intramucosal neoplasia lesions (34.9%), 132 high-grade intramucosal neoplasia lesions (50.6%), 13 submucosal invasive cancer lesions (5.0%), and 25 deep submucosal invasive cancer lesions (9.6%). The coincidence rate between endoscopic prediction and pathological diagnosis of these lesions was 55.6% (145/ 261). The macroscopic type and size of the lesions were significantly associated with the diagnostic accuracy of JNET type 2B lesions (P < 0.001). There was a significant difference in the diagnostic accuracy among the lesions with different pit pattern types (P < 0.001).

OBJECTIVE

Both the macroscopic type and size affect the accuracy of endoscopic diagnosis of JNET type 2B colorectal lesions. JNET classification combined with pit pattern types can have better accuracy in predicting the pathological diagnosis of these lesions.

Electrospray Ionization Inside the Ion Inlet Tube: Multijet Mode Operation

We investigated the electrospray ionization inside the narrow channel of the ion inlet tube. An insulating emitter capillary made of fused silica with a 0.2 mm outer diameter was inserted into the ion inlet tubes with a 0.5 and 0.6 mm inner diameter to aspirate all the charged droplets. A custom-made ion inlet tube with two side holes near its entrance is used to observe the spraying condition. The spray current is measured and monitored during the MS acquisition using isolation amplifiers. Because the emitter is cylindrically surrounded in close proximity by the metallic inner wall, it is difficult to obtain a stable and symmetric Taylor cone with its apex at the center of the emitter. Instead, a stable operation under a flow rate of 1-4 μL/min is found to be in the form of a multicone-jet mode with two or more Taylor cones anchoring around the rim of the emitter. The emitted charged droplet jets are dragged from hitting the wall by the fast-flowing air inside the inlet tube. Comparison with the typical cone-jet and multijet mode operated several millimeters outside the inlet capillary shows signal enhancements for protein standards.

SGN nerve filaments develop synapses with IHCs earlier than with OHCs in C57BL/6 mouse inner ear

OBJECTIVE

To explore the connections between hair cells and spiral ganglion neurons (SGNs) during the development of the C57BL/6 mouse inner ear.

MATERIALS AND METHODS

The specimens of C57BL/6 mouse inner ear, from E15 (embryo day 15) to adult mouse, were collected; immunohistochemistry was employed to explore the frozen sections of specimens.

RESULTS

The development of cochlea starts sequentially from the basal turn to the apex turn. Morphological development of SGNs occurs mainly from E16 to P12 (postnatal day 12). Hair cells appear from E18 to P12, and inner hair cells (IHCs) develop earlier than outer hair cells (OHCs). The connections between hair cells and SGNs begin to develop during E18-P1, morphologically resemble mature synapses during P8-P12, and completely mature in adult mice.

CONCLUSIONS

The genesis of auditory ribbon synapse occurs from E18 to P1. Synchronized with the development of SGNs and hair cells, the functional filaments remain connected to hair cells, while the spare ones get disconnected from the surface of hair cells. Connections between SGN nerve filaments and IHCs occur earlier than those between SGN nerve filaments and OHCs.

Effects of supplementation of sea buckthorn press cake on mycelium growth and polysaccharides of Inonotus obliquus in submerged cultivation

AIMS

Investigation of the influence of cultivation time and sea buckthorn press cake (Hippophaë rhamnoides) dosage on mycelium yield of Inonotus obliquus in submerged cultivation and on the yield, monomer composition, and macromolecular properties of the exopolysaccharides (EPS) from culture media and intracellular polysaccharides (IPS) extracted from mycelia.

METHODS AND RESULTS

Supplementation at 5 g l^-1 combined with cultivation time of 250 h granted highest yield increase in mycelia (by 122%). The supplementation reduced extraction yield and decreased the molecular weight of the main IPS population. The supplementation increased production and molecular weight of EPS. The relative content of arabinose and rhamnose in EPS positively correlated with dosage of the press cake. The press cake supplementation increased the content of galacturonic acid in IPS, but not in EPS.

CONCLUSION

Sea buckthorn press cake is a food industry fibrous side stream with high oil content. It increases the cultivation yield of Inonotus obliquus mycelium and influences the produced polysaccharides.

SIGNIFICANCE AND IMPACT OF THE STUDY

Mycelium is a resource of bioactive polysaccharides, attracting the interest of nutraceutical companies. Sea buckthorn press cake is a promising supplement for increasing mycelium production. The utilization of this agricultural side stream would therefore favour circular economy.

Spatial variation of the soil bacterial community in major apple producing regions of China

AIMS

In China, apple production areas are largely from the coastal to inland areas and across varied climate zones. However, the relationship among soil micro-organisms, environmental factors and fruit quality has not been clearly confirmed in orchards. Here we attempted to identify the variation of soil bacteria in the main apple producing regions and reveal the relationship among climatic factor, soil properties, soil bacterial community and fruit quality.

METHODS AND RESULTS

Sixty soil samples were collected from six main apple producing areas in China. We examined the soil bacteria using bacterial 16S rRNA gene amplicon profiling. The results show that the soil bacterial diversity of apple orchards varied from the Bohai Bay Region to the Loess Plateau Region. Proteobacteria, Acidobacteria and Actinobacteria were the predominant taxa at the phylum level for all six areas. In the Bohai Bay and the Loess Plateau region, which are the two largest apple producing areas, Proteobacteria and Actinobacteria had the highest relative abundance, respectively. Furthermore, soil bacterial diversity showed positive correlation with the mean annual temperature (MAT), soil organic matter (SOM) and pH. Excluding a direct effect on the apple fruit quality, MAT exerted an indirect influence through soil SOM and pH to alter the relative abundance of dominant taxa and shift the bacterial diversity, which affects the apple fruit titratable acids and soluble solids.

CONCLUSIONS

Geographic variables underlie apple orchard soil bacterial communities vary according to spatial scale. Environmental factors exert an indirect effect on apple fruit quality via shaping soil bacterial community.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides a list of bacteria associated with environmental factors and the ecological attributes of their interactions in apple orchards, which will improve our ability to promote soil bacterial functional capabilities in order to reduce the fertilizer input and enhance the fruit quality.

Influence of mesenchymal stem cells on respiratory distress syndrome in newborn swines via the JAK-STAT signaling pathway

OBJECTIVE

Acute respiratory distress syndrome (ARDS) threatens humans' health worldwide, causing huge labor and economic cost investment. This study aims to explore whether mesenchymal stem cells (MSCs) affect RDS in newborn swines via the Janus kinase-signal transducers and activators of transcription (JAK-STAT) signaling pathway by the establishment of the model of the disease.

MATERIALS AND METHODS

The phosphorylation of the JAK-STAT signal transduction proteins was first detected via Western blotting to verify the regulatory effect of MSCs on RDS in newborn swines through the JAK-STAT signaling pathway. Then, the Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was utilized to analyze the influences of the injection of MSCs into the blood of newborn model RDS swines on inflammatory factors in vivo. To further demonstrate the signal transduction function put forwarded, the RT-PCR and enzyme-linked immunosorbent assay (ELISA) were adopted to analyze the influences of the JAK-STAT signaling pathway inhibitor on the expression of the signature proteins of RDS in newborn swines and the changes in the inflammatory factors.

RESULTS

MSCs induced the phosphorylation of JAK and STAT, and they activated the JAK-STAT signal transduction of RDS in newborn swines. Compared with those in normal saline group, the interleukin (IL)-2, IL-6, IL-8, and tumor necrosis factor-α (TNF-α) expression levels in MSC group were increased, namely, MSCs substantially promoted their expression levels (p<0.05), but those of IL-10 and IL-13 were significantly decreased (p<0.05).

CONCLUSIONS

The inhibitor of the JAK-STAT signaling pathway can suppress the therapeutic effect of MSCs on RDS in newborn swines.

PERSPECTIVE: Critical Cooling and Warming Rates as a Function of CPA Concentration

Cryoprotective agents (CPAs) are routinely applied in cryopreservation protocols to achieve the vitrified state thereby avoiding the damaging effects of ice crystals. Once the CPA has been added, the system needs to cool at a rate ≥ critical cooling rate (CCR) to avoid ice crystallization and successfully enter the vitrified state. Subsequently, upon warming the system needs to meet or exceed a critical warming rate (CWR), often one to two orders of magnitude higher than the CCR, to avoid ice formation and return the system to physiological temperatures for use. Many experimental and theoretical studies have been published on CCRs and CWRs, and correlation for these rates as a function of concentration has been explored for some single component CPAs, but not the CPA cocktails which are commonly used in tissue and organ cryopreservation. In this paper, we summarize the available data of CCRs and CWRs for a variety of CPAs, and suggest a convenient mathematical expression for CCR and CWR that can guide general use for cryoprotective protocol, but also highlights the critical need for further study on CPA cocktails and tissue systems in which CPAs may behave differently and/or may not be fully equilibrated to the loaded CPA.

Time-resolved in situ monitoring of photocatalytic reactions by probe electrospray ionization mass spectrometry

Probe electrospray ionization mass spectrometry (PESI-MS) has been demonstrated to be a useful in situ and online analytical technique for monitoring of various reactions. In this work, PESI-MS with a surface-modified probe was adopted and applied to in situ monitoring of photocatalytic reactions. Typical reactions of semiconductor photocatalysts, namely TiO₂, SnO₂, WO₃, SiC and ZnS catalyzed methylene blue (MB) and brilliant green (BG) degradation, were selected to demonstrate the potential of PESI-MS to monitor heterogeneous photocatalytic reactions occurring in suspensions. Surface modification of the probe ensures increased wettability during the whole monitoring process. PESI-MS could provide continuous sampling and real-time MS results without time-consuming and cumbersome sample pretreatments. This method has other merits including good reproducibility and stability (time scale > 60 min), convenience of operation, low sample consumption, high time resolution and high tolerance to suspended photocatalyst particles. Time-resolved mass spectra and ion chromatograms of every chemical species e.g. the substrate and reactive intermediates could be obtained, which is helpful for a better understanding of the photocatalytic reaction process. Thus, PESI-MS could be a versatile analytical technique for in situ photocatalytic reaction analysis and could be an alternative means for the evaluation of photocatalyst performance.

Ultrafast temporal-spatial dynamics of amorphous-to-crystalline phase transition in Ge2Sb2Te5 thin film triggered by multiple femtosecond laser pulses irradiation

Studies have shown that the crystallization phase state of Ge₂Sb₂Te₅ (GST) can be reversibly modulated by femtosecond (fs) laser multiple pulses, which have excellent applications in reconfigurable multi-level operation fields. In this study, the temporal-spatial crystalline evolution dynamics of amorphous GST film is investigated during two fs laser pulses excitation through a pump-probe shadowgraph imaging technique. A quasi-amorphous phase state, which is different from that in the initial as-deposited amorphous GST, is emerged through the first fs laser pulse excitation with a pulse energy lower than crystallization threshold. The experimental results reveal that a crystallization enhancement effect can be induced through the second pulse excitation based on this quasi-amorphous surface structure. The stimulative cluster generated in the quasi-amorphous reduces the amorphous-to-crystalline phase transition threshold for the second fs laser pulse irradiation. The spatially-resolved phase-transition threshold extension effect in a horizontal direction is proposed with the increasing pulse number to summarize the mechanism of the crystallization enhancement effect. The specific-grain-appearance (coarse grains and fine grains representing different phase transition approach) distributed area induced by single and double fs laser pulses irradiation are experimentally demonstrated corresponding to threshold extension theory.

Solubility Enhancement of Myricetin by Inclusion Complexation with Heptakis-O-(2-Hydroxypropyl)-β-Cyclodextrin: A Joint Experimental and Theoretical Study

Four cyclodextrins (CD) including β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), heptakis-O-(2-hydroxypropyl)-β-cyclodextrin (HP-β-CD), and heptakis-O-(2, 6-di-O-methyl)-β-cyclodextrin (DM-β-CD) were used as solubilizer to study the solubility enhancement of myricetin. The results of the phase solubility study showed that the presence of CDs could enhance the solubility of myricetin by forming 1:1 complexes. Among all CDs, HP-β-CD had the highest solubilization effect to myricetin. The concentration of myricetin could be 1.60 × 10^-4 moL/L when the presence of HP-β-CD reached 1.00 × 10^-2 moL/L, which was 31.45 times higher than myricetin's aqueous solubility. Subsequently, the HP-β-CD:myricetin complex was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). In order to get an insight of the plausible structure of the complex, molecular docking was used to study the complexation process of HP-β-CD and myricetin. In the complex, the A ring and C ring of myricetin were complexed into the hydrophobic cavity of HP-β-CD, while the ring B was located at the wide rim of HP-β-CD. Four hydrogen bonding interactions were found between HP-β-CD and -OH groups of the guest in the HP-β-CD: myricetin complex. The complexation energy (△E) for the host-guest interactions was calculated with a negative sign, indicating the formation of the complex was an exergonic process. A 30-ns molecular dynamics simulation was conducted to the HP-β-CD: myricetin complex. Calculation results showed that no large structural deformation or position change were observed during the whole simulation time span. The average root-mean-square deviation (RMSD) changes of the host and guest were 2.444 and 1.145 Å, respectively, indicating the complex had excellent stability.

Apple rootstocks with different phosphorus efficiency exhibit alterations in rhizosphere bacterial structure

AIMS

The purpose of this study was to select phosphorus-efficient apple rootstocks under phosphorus deficiency and to reveal the effects of different apple rootstocks on the rhizosphere bacterial community.

METHODS AND RESULTS

We used 83 hybrid lines of Malus robusta Rehd. × Malling 9 (M.9) to investigate their physiological traits and the phosphorus deficiency phenotypes of leaves in response to phosphorus deficiency (0·1 mmol l^-1 PO₄ ^3- ). All the plants were cultivated in pots in the greenhouse and watered using drip irrigation. In accordance with the results of investigation, we selected the phosphorus-efficient hybrid lines (PE) and the phosphorus-inefficient hybrid lines (PI) to research their root morphology and root hairs (RH). In addition, we used Illumina MiSeq sequencing to determine the bacterial community of the rhizosphere from different rootstocks. The results showed that the PE plants had better growth characteristics and stronger root plasticity than that of the PI plants, and phosphorus deficiency can stimulate the RH growth of PE plants. There was no significant difference in the rhizosphere bacterial diversity, but we found that the bacterial community structure was significantly different at the genus levels; in addition, 89 genera were found to have significant differences between PE and PI plants, especially Bacillus. The PE rhizosphere had more abundant Bacillus compared to the PI. High positive Pearson correlations with the phosphorus concentration in the plantlets of apple rootstocks were detected for the bacterial genera Bacillus (r: 0·776).

CONCLUSIONS

The phosphorus-efficient apple rootstocks adapted to phosphorus deficiency by shaping the root morphology. Notably, different apple rootstocks showed alteration of the microbes in rhizosphere.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study can provide the materials for exploring the mechanism of apple rootstock phosphorus absorption. In accordance with the different bacterial community compositions, we can develop the inoculants to promote nutrient uptake.

HIV-1 genotype is independently associated with immunodeficiency progression among Chinese men who have sex with men: an observational cohort study

OBJECTIVES

HIV-1 genetic diversity is increasing among men who have sex with men (MSM) in China, but the association of HIV-1 genotype with disease progression remains to be elucidated.

METHODS

We collected data in an observational longitudinal cohort study of 860 HIV-1-infected MSM in Guangzhou, China between January 2008 and March 2017. Kaplan-Meier analysis and Cox proportional hazard model were used to predict the time from HIV-1 diagnosis to immunodeficiency progression (CD4 cell count < 200 cells/μl) as well as adjusted hazard ratio (aHR).

RESULTS

CRF01_AE and HIV-1 subtype B infection were associated with higher percentage of patients progressed to immunodeficiency and higher incidence of immunodeficiency than infection with CRF07_BC or CRF55_01B. Compared with CRF07_BC, the time from HIV-1 diagnosis to immunodeficiency were different among the major HIV-1 genotypes, which ranked as follows, in descending order: CRF07_BC (7.03 years) > CRF55_01B (5.71 years, P = 0.014; aHR 3.752, P = 0.0923) > CRF01_AE (5.18 years, P < 0.001; aHR 4.733, P = 0.0152). HIV-1 genotype, viral load and baseline CD4 T-cell count were three independent variables associated with disease progression.

CONCLUSIONS

Our results confirm differential rates of immunodeficiency progression as a function of HIV-1 genotype. The impact of HIV-1 genotype on HIV epidemics, patient management and prevention should be further investigated.

Role of Adult Tissue-Derived Pluripotent Stem Cells in Bone Regeneration

Background

Bone marrow-derived mononuclear cells (BM-MNC) consist of a heterogeneous mix of mesenchymal stem cells (MSC), hematopoietic progenitor cells (HPC), endothelial progenitor cells (EPC), monocytes, lymphocytes and pluripotent stem cells. Whereas the importance of MSC and EPC has been well documented in bone healing and regeneration studies, the role of pluripotent stem cells is still poorly understood. In the present study we evaluated if and how Very Small Embryonic Like cells (VSEL), isolated from rat BM-MNC, contribute to bone healing.

Methods

Large bone defects were made in the femurs of 38 Sprague Dawley female rats and treated with β-TCP scaffold granules seeded with male VSEL; BM-MNC, VSEL-depleted BM-MNC or scaffold alone, and bone healing was evaluated at 8 weeks post-surgery.

Results

Bone healing was significantly increased in defects treated with VSEL and BM-MNC, compared to defects treated with VSEL-depleted BM-MNC. Donor cells were detected in new bone tissue, in all the defects treated with cells, and in fibrous tissue only in defects treated with VSEL-depleted BM-MNC. The number of CD68+ cells was the highest in the VSEL-depleted group, whereas the number of TRAP positive cells was the lowest in this group.

Conclusions

Based on the results, we can conclude that VSEL play a role in BM-MNC induced bone formation. In our rat femur defect model, in defects treated with VSEL-depleted BM-MNC, osteoclastogenesis and bone formation were decreased, and foreign body reaction was increased.

[The hemodynamic study of internal jugular vein in patients with pulsatile tinnitus by color doppler sonography]

Objective:To investigate the hemodynamic changes of internal jugular vein（IJV） in patients with pulsatile tinnitus（PT） detected by color doppler sonography（CDS）. To explore the correlation of PT with IJV drainage dominance and the value of CDS in the diagnosis of PT. Method:Two hundred and twenty-one patients with PT were examined with the CDS and IJV compression test. The hemodynamic data of the upper, middle and lower IJV were compared with both PT side and unaffected side. The correlation of the PT with the IJV drainage dominance was analyzed. Result:A total of 125 cases（56.6%） of 221 patients with PT underwent ultrasonic IJV compression test with positive results, 96 cases（43.3%） with negative results. In the positive compression test group, the tinnitus disappeared after IJV being completely compressed in 109 cases（87.2%）, and in 16 cases（12.8%） after IJV being partial closure. The extent of sectional area reduction was: upper jugular vein（75.41 ±9.39）%, middle jugular vein（80.25±13.16）%, lower jugular vein（86.58± 7.53）%. The blood flow volume on the tinnitus side was obviously higher than that on the unaffected side（P=0.001）. In the negative compression test group, there was no significant difference in blood flow volume between tinnitus side and unaffected side. In the IJV positive compression test group, 54 cases（43.2%） were IJV drainage dominance combined, and 71 cases（56.8%） were non-dominant combined. In the IJV negative compression test group, 24 cases（25%） were IJV drainage dominance combined, and 72 cases（75%） were non-dominant combined. Conclusion:The positive result of IJV compression test using CDS and the flow volume of IJV on the affected side significantly higher than that on the unaffected side contributed to the diagnosis of venous PT. In this study, the IJV non-dominant side was more common in the venous PT.

P4671A well-defined subgroup of chronic thromboembolic pulmonary hypertension patients are positive for antiphospholipid antibodies

Introduction

Recurrent thromboembolism is a major risk factor for chronic thromboembolic pulmonary hypertension (CTEPH). Antiphospholipid antibodies (aPL) are a recognized risk factor for recurrent thromboembolism, however, their contribution to the development of CTEPH is currently unknown.

Purpose

The aim of this study was to evaluate the prevalence of antiphospholipid autoantibodies in a large cohort of consecutive patients with CTEPH.

Methods

Starting May 2013 to December 2018, 297 CTEPHpatients were consecutively enrolled. Diagnosis was confirmed with standardized right heart catheterization, 2D or/and 3D pulmonary angiography in all patients.All patients were also screened for thrombophilia including lupus anticoagulant IgG/IgM anticardiolipin antibodies and IgG/IgM aβ2GPI antibodies. Clinical and demographic characteristics, laboratory profile and hemodynamic data were compared between patients with aPL positive and aPL negative laboratory profiles.

Results

Overall, 297 consecutive patients with CTEPH were assessed for aPLs. Of these, 23 patients (7.7%) resulted positive for laboratory tests exploring aPL. Among patients with positive aPL, profile 17 (74%) were positive for all three test exploring aPL (LA+, aCL+, aB2GPI+). When compared to CTEPH patients without aPL test positivity, those positive for aPL were significantly younger (30.0 vs 55.6 years, p<0.0001), had a positive history of pulmonary embolism (95.6% vs 65.7%, p=0.003), deep venous thrombosis (78.3% vs 41.9%, p=0.0008) and were more frequently affected by other autoimmune diseases (43.5% vs 2.9%, p<0.0001). Moreover, positive aPL patients showed better hemodynamics on right heart catheterization, had more proximal lesions, and had more frequently level I and II surgical classification (82.6% vs 40.5%, p=0.0002) on pulmonary angiography.

Conclusions

These findings suggest that young patients with pulmonary embolism should be assessed for aPLs to guide anticoagulation therapy and prevent recurrences. Additionally, younger age, more proximal lesions and less severe hemodynamic profiles make majority patients with APS good candidates for PEA surgery.

[Analysis of the effect and influencing factors of customized sound on tinnitus]

Objective:To explore the effect and influencing factors of customized sound on tinnitus. Method:303 patients with tinnitus who received customized sound therapy for 6 months were enrolled in this study. Tinnitus handicap inventory (THI) was used to evaluate the treatment effect before treatment, 1 month, 2 months, 3 months, 4 months, 5 months and 6 months after treatment, and the influencing factors of sound treatment effect were analyzed. Result:The THI score decreased at the 1, 2, 3, 4, 5 and 6 months after treatment (P<0.01), compared with that before treatment. Gender, tinnitus type and presence or absence of voice allergy had no effect on THI score before treatment and 6 months after treatment (P>0.05). Conclusion:Customized sound therapy can reduce the score of THI in tinnitus patients, which supports that sound therapy can reduce the negative impact and disturbances produced by tinnitus, and its curative effect is not affected by gender, tinnitus type and presence or absence of voice allergy..

Electrical stimulation shifts healing/scarring towards regeneration in a rat limb amputation model

Different species respond differently to severe injury, such as limb loss. In species that regenerate, limb loss is met with complete restoration of the limbs’ form and function, whereas in mammals the amputated limb’s stump heals and scars. In in vitro studies, electrical stimulation (EStim) has been shown to promote cell migration, and osteo- and chondrogenesis. In in vivo studies, after limb amputation, EStim causes significant new bone, cartilage and vessel growth. Here, in a rat model, the stumps of amputated rat limbs were exposed to EStim, and we measured extracellular matrix (ECM) deposition, macrophage distribution, cell proliferation and gene expression changes at early (3 and 7 days) and later stages (28 days). We found that EStim caused differences in ECM deposition, with less condensed collagen fibrils, and modified macrophage response by changing M1 to M2 macrophage ratio. The number of proliferating cells was increased in EStim treated stumps 7 days after amputation, and transcriptome data strongly supported our histological findings, with activated gene pathways known to play key roles in embryonic development and regeneration. In conclusion, our findings support the hypothesis that EStim shifts injury response from healing/scarring towards regeneration. A better understanding of if and how EStim controls these changes, could lead to strategies that replace scarring with regeneration.

Single-molecule characterization of extrinsic transcription termination by Sen1 helicase

Extrinsic transcription termination typically involves remodeling of RNA polymerase by an accessory helicase. In yeast this is accomplished by the Sen1 helicase homologous to human senataxin (SETX). To gain insight into these processes we develop a DNA scaffold construct compatible with magnetic-trapping assays and from which S. cerevisiae RNA polymerase II (Pol II), as well as E. coli RNA polymerase (ecRNAP), can efficiently initiate transcription without transcription factors, elongate, and undergo extrinsic termination. By stalling Pol II TECs on the construct we can monitor Sen1-induced termination in real-time, revealing the formation of an intermediate in which the Pol II transcription bubble appears half-rewound. This intermediate requires ~40 sec to form and lasts ~20 sec prior to final dissociation of the stalled Pol II. The experiments enabled by the scaffold construct permit detailed statistical and kinetic analysis of Pol II interactions with a range of cofactors in a multi-round, high-throughput fashion.

Yeast’s Sen1 helicase is involved in the suppression of antisense transcription from bidirectional eukaryotic promoters. Here authors develop and utilize a quantitative single-molecule assay reporting on the kinetics of extrinsic eukaryotic transcription termination by the Sen1 helicase and a reaction intermediate in which the Pol II transcription bubble appears half-rewound.

Key factors determining variations in RNA interference efficacy mediated by different double-stranded RNA lengths in Tribolium castaneum

Double-stranded RNA (dsRNA) length may affect RNA interference (RNAi) efficacy. Herein, variation in RNAi efficacy associated with dsRNA molecular length was confirmed via comparison of knockdown results following dsRNA injection into Tribolium castaneum. Through in vitro experiments with T. castaneum midgut, dsRNA accumulation in the midgut, degradation by midgut homogenates and persistence in haemolymph after injection were tested to determine the causes of RNAi efficacy variation. The comparative efficacies of dsRNAs were 480 bp ≈ 240 bp > 120 bp > 60 bp >> 21 bp. The combined midgut dsRNA accumulation and midgut homogenate-induced degradation analyses suggested cellular uptake to be the key barrier for 21 bp dsRNA functioning, but was likely not the main determinant of the variation in longer dsRNAs' (≥60 bp) bioactivity. In vitro RNAi experiment with T. castaneum midgut showed that long dsRNAs all significantly depleted the expression of corresponding genes, suggesting little variation in intracellular RNAi machinery's affinity for different dsRNA lengths. In vivo haemolymph content dynamics of different dsRNAs following injection indicated higher persistence of longer dsRNAs. In addition, comparison of the in vivo and in vitro RNAi efficacy also indicated the importance of haemolymph degradation. Thus, the varied efficacy of long dsRNAs resulted from their degradation by nucleases, which varied with dsRNA length.