Two-dimensional spin-crossover coordination polymers based on the 1,1,2,2-tetra(pyridin-4-yl)ethene ligand

A series of two-dimensional (2D) spin-crossover coordination polymers (SCO-CPs) [FeII(TPE)(NCX)2]·solv (1: X = BH3, solv = H2O·2CH3OH·DMF; 2: X = Se, solv = H2O·2CH3OH·0.5DMF; 3: X = S, solv = H2O·2CH3OH·0.5DMF) were synthesized by employing 1,1,2,2-tetra(pyridin-4-yl)ethene (TPE) and pseudohalide (NCX-) coligands. Magnetic measurements indicated that complexes 1-3 exhibited SCO behaviors with diminishing thermal hysteresis (7/4/0 K) upon decreasing the ligand-field strength. The critical temperatures (Tc) during spin transition were found to be inversely proportional to the coordination ability parameters (a™) with a linear correlation. The guest effect was also investigated in the solvent-exchanged phases 1-SE/2-SE/3-SE wherein the DMF molecules were replaced by methanol molecules. Compared with 1-3, 1-SE/2-SE/3-SE displayed more abrupt and complete single-step SCO behaviors but narrower thermal hysteretic loops. The results reported here demonstrate that the Tc values of these two families were dominated by the ligand-field strength of the NCX- anions (NCBH3 > NCSe > NCS), whereas the guest effect only modulated the kinetic factor of the SCO nature in this system.

Cyanometallic charge engineering in spin crossover metal-organic frameworks

In this study, we successfully synthesize cationic/neutral/anionic inverse-Hofmann-type spin crossover (SCO) frameworks with 1,1,2,2-tetrakis(4-(pyridine-4-yl)phenyl)-ethene ligand by means of cyanometallic charge engineering strategy. The cationic and neutral frameworks exhibit single-step thermally induced spin transition behaviors, while the SCO capability of anionic framework can be aroused by partial desolvation. This strategy provides a new idea to construct ionic SCO frameworks and extends the toolkit for SCO materials.

Single-Crystal Transformation Engineering the Spin Change of Metal-Organic Frameworks via Cluster Deconstruction

Spin crossover (SCO) materials with new architectures will expand and enrich the research in the SCO field. Here, we report two metal-organic frameworks (MOFs) containing tetradentate organic ligands and hexatopic linkers [Ag8 X8 (CN)6 ]6- (X=Br and I), which represents the first SCO MOF with clusters as building blocks. The silver halide cluster can be further removed after reacting with lithium tetracyanoquinodimethan (LiTCNQ). Such post-synthetic modification (PSM) is realized via single-crystal to single-crystal (SCSC) transformation from urk to nbo topology. Accordingly, the spin state and fluorescence properties are greatly modified by cluster deconstruction. Therefore, these achievements will provide new ideas for the design of new SCO systems and the development of PSM methods.

Demographics, Medical Comorbidities, and Functional Factors Associated with Radiation Therapy Regimen Length in Older Patients

PURPOSE/OBJECTIVE(S)

To determine demographic, comorbidity, and functional factors associated with radiation therapy (RT) regimen length in older patients.

MATERIALS/METHODS

Using data from the Medicare Current Beneficiary Survey (MCBS), we identified patients who were diagnosed with cancer from 2002-2019 and received RT. The MCBS dataset is comprised of linked patient survey and Medicare claims data. Days of RT were used as a proxy for fractions of RT each patient received. We used treatment guidelines to identify a minimum treatment threshold for each cancer type to differentiate patients with low RT utilization from normal or supra-palliative RT utilization. Statistical analyses of patient demographics, comorbidities, and activities of daily living (ADL) were performed using chi-square and t-tests.

RESULTS

A total of 880 patients were included in this analysis, of whom 669 had high RT utilization. Of the demographic factors considered, age 85+ was associated with longer RT regimen length (p = 0.045), as was being "other" or multi-race, community, or facility treatment setting, and residing in the south (p = 0.013, 0.006, 0.003, 0.038, respectively). Of medical comorbidities, only lung disease was associated with longer RT regime (p = 0.020). Longer RT regimen length was significantly associated with requiring assistance with any ADLs (bathing, dressing, eating, chair, walking, toileting, all with p <0.001).

CONCLUSION

This abstract identifies specific patient demographics, medical comorbidities, and ADL limitations which may be associated with RT regimen length in older patients. Future work should focus on optimizing patients and delivery systems for RT and the relationship between pre- and post-treatment ADLs.

[Comparison of the efficacy of thulium fiber laser and holmium laser lithotripsy in the treatment of upper urinary tract stones]

Objective: To compare the efficacy of thulium fiber laser (TFL) and holmium laser (HL) in the treatment of upper urinary tract stones. Methods: A total of 76 patients diagnosed with upper urinary tract stones by radiographic examination and who required ureteroscopy lithotripsy or retrograde intrarenal stone surgery were prospectively enrolled from the Department of Urology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine between January 2022 and June 2022. Patients were divided into TFL group (n=38) and HL group (n=38) in a 1∶1 ratio according to the randomization schedule. The perioperative outcomes and stone-free rate of two groups were recorded and compared. Results: Finally, the clinical data of 71 patients were completely collected, including 55 males and 16 females, with a mean age of (45.7±14.1) years old. There were 36 patients in TFL group and 35 patients in HL group, and there was no significant difference in age, body mass index, gender, Charlson comorbidity index, stone site, stone location, stone size and stone density between two groups (all P>0.05). All the surgeries were successfully performed with no intraoperative complications. There were no significant differences between the two groups in terms of operation time, stone displacement during lithotripsy, visual field clarity, changes in hemoglobin, leukocyte, and C-reactive protein, and length of postoperative hospital stay (all P>0.05), but the laser action time[M (Q1,Q3)] in the TFL group was 30.0 (20.0, 48.8)s, which was significantly shorter than that in the HL group [90.0 (50.0, 120.0)s, P<0.001]. The stone-free rates of TFL group and HL group were 97.2% (35/36) and 88.6% (31/35), and there was no significant difference (P=0.337). The postoperative complication incidences of TFL group and HL group were 36.1% (13/36)and 22.9% (8/35), respectively, and the difference was not significant either (P=0.221). For ureter stones, the laser action time in TFL group was 22.5 (20.0, 43.8)s, which was significantly shorter than that in HL group [80.0 (50.0, 120.0)s, P<0.001]. For stones with maximum diameter≤10 mm, the laser action time in TFL group was 20.0 (10.0, 25.0)s, which was significantly shorter than that in HL group [50.0 (40.0, 80.0)s, P<0.001]. For stones with maximum diameter>10 mm, the laser action time in TFL group was 60.0(42.5, 180.0)s, which was significantly shorter than that in HL group [180.0(120.0, 210.0)s, P=0.035]. For stones with density≤1 000 CT, the laser action time in TFL group was 30.0 (20.0, 45.0)s, which was significantly shorter than that in HL group [95.0 (47.5, 120.0), P=0.001]. For stones with density>1 000 CT, the laser action time in TFL group was 30.0 (20.0, 90.0)s, which was significantly shorter than that in HL group [80.0 (55.0, 180.0)s, P=0.033]. Conclusion: TFL lithotripsy is an effective and safe surgical procedure for the treatment of upper urinary tract stones, with similar clinical efficacy but shorter laser action time compared to HL lithotripsy.

[Cardiac amyloidosis: pathological classification and clinical analysis of 48 cases]

Objective: To investigate the histological features and clinical manifestations in different types of cardiac amyloidosis to improve diagnostic accuracy. Methods: The histopathological features and clinical manifestations of 48 patients diagnosed with cardiac amyloidosis by Congo red stain and electron microscopy through endomyocardial biopsy were collected in West China Hospital of Sichuan University from January 2018 to December 2021. Immunohistochemical stains for immunoglobulin light chains (κ and λ) and transthyretin protein were carried out, and a review of literature was made. Results: The patients age ranged from 42 to 79 years (mean 56 years) and the male to female ratio was 1.1 to 1.0. The positive rate of endomyocardial biopsy was 97.9% (47/48), which was significantly higher than that of the abdominal wall fat (7/17). Congo red staining and electron microscopy were positive in 97.9% (47/48) and 93.5% (43/46), respectively. Immunohistochemical stains showed 32 cases (68.1%) were light chain type (AL-CA), including 31 cases of AL-λ type and 1 case of AL-κ type; 9 cases (19.1%) were transthyretin protein type (ATTR-CA); and 6 cases (12.8%) were not classified. There was no significant difference in the deposition pattern of amyloid between different types (P>0.05). Clinical data showed that ATTR-CA patients had less involvement of 2 or more organs and lower N-terminal pro-B-type natriuretic peptide (NT-proBNP) than the other type patients (P<0.05). The left ventricular stroke volume and right ventricular ejection fraction of ATTR-CA patients were better than the other patients (P<0.05). Follow-up data of 45 patients was obtained, and the overall mean survival time was 15.6±2.0 months. Univariate survival analysis showed that ATTR-CA patients had a better prognosis, while cardiac amyloidosis patients with higher cardiac function grade, NT-proBNP >6 000 ng/L, and troponin T >70 ng/L had a worse prognosis (P<0.05). Multivariate survival analysis showed that NT-proBNP and cardiac function grade were independent prognostic factors for cardiac amyloidosis patients. Conclusions: AL-λ is the most common type of cardiac amyloidosis in this group. Congo red staining combined with electron microscopy can significantly improve the diagnosis of cardiac amyloidosis. The clinical manifestations and prognosis of each type are different and can be classified based on immunostaining profile. However, there are still a few cases that cannot be typed; hence mass spectrometry is recommended if feasible.

Comparison between Dual-Energy CT and Quantitative Susceptibility Mapping in Assessing Brain Iron Deposition in Parkinson Disease

BACKGROUND AND PURPOSE

Both dual-energy CT and quantitative susceptibility mapping can evaluate iron depositions in the brain. The purpose of this study was to compare these 2 techniques in evaluating brain iron depositions in Parkinson disease.

MATERIALS AND METHODS

Forty-one patients with Parkinson disease (Parkinson disease group) and 31 age- and sex-matched healthy controls (healthy control group) were included. All participants underwent brain dual-energy CT and quantitative susceptibility mapping. ROIs were set bilaterally in the globus pallidus, substantia nigra, red nucleus, caudate nucleus, and putamen. CT values and magnetic susceptibility values were obtained in each ROI. Differences in CT values and magnetic susceptibility values between the Parkinson disease and healthy control groups were compared, followed by analysis of receiver operating characteristic curves. Correlations between CT values and magnetic susceptibility values were then evaluated.

RESULTS

The CT values of the bilateral globus pallidus, substantia nigra, and red nucleus were higher in the Parkinson disease group (P < .05). The magnetic susceptibility values of the bilateral globus pallidus and substantia nigra were higher in the Parkinson disease group (P < .05). The CT value of the right globus pallidus in linear fusion images had the highest diagnostic performance (0.912). Magnetic susceptibility values of the bilateral globus pallidus in the Parkinson disease group were positively correlated with CT values at the level of 80 kV(peak), linear fusion images, and SN150 kV(p) (r = 0.466∼0.617; all, P < .05).

CONCLUSIONS

Both dual-energy CT and quantitative susceptibility mapping could assess excessive brain iron depositions in Parkinson disease, and we found a positive correlation between CT values and magnetic susceptibility values in the bilateral globus pallidus.

[Influencing factors for postoperative survival of patients with pneumoconiosis treated by lung transplantation]

Objective: To explore the influencing factors for postoperative survival of patients with pneumoconiosis (silicosis) after lung transplantation in order to improve their clinical outcomes. Methods: In August 2021, retrospective alalysis from December 2015 to July 2021, 29 patients with end-stage pneumoconiosis underwent lung transplantation at Department of Thoracic Surgery, Affiliated Henan Provincial People's Hospital, Zhengzhou University. The survival, postoperative complications, and causes of death were analyzed. Life table and Kaplan-Meier method were used to draw survival curves, the log-rank test was used to compare the influence of each factor on survival rates, and the multivariate Cox proportional hazards regression model was used to evaluate the influence of each factor on survival. Results: All the patients underwent successful lung transplantation, with survival rates of 75% at 6 months, 70% at 1 year, 65% at 2 years, 50% at 3 years and 50% at 5 years. The Kaplan-Meier survival analysis showed that BMI, age and preoperative albumin level were influencing factors for postoperative survival rates (P<0.05) . The multivariate COX regression model showed that BMI≥18.5 kg/m(2) and the albumin level≥35 g/L were the protective factors (P<0.05) . Conclusion: Aging older, preoperative BMI<18.5 kg/m(2) and hypoalbuminemia are independent risk factors for death after lung transplantation. Survival rates are affected by preoperative BMI index, albumin level and age. Early intervention should be made before lung transplantation to promote the BMI index and albumin level to reach the standard.

Critical body fat percentage required for puberty onset: the Taiwan Pubertal Longitudinal Study

PURPOSE

Prepubescent body fat percentage (BFP) is associated with puberty onset; however, the association between the timing of puberty onset and BFP remains unclear. This study aimed to determine whether and how the timing of puberty onset is associated with various anthropometric measures, and to investigate the critical time period of the BFP transition before and after puberty.

METHODS

The Taiwan Pubertal Longitudinal Study (TPLS) has a multicenter, population-based prospective cohort and was established in July 2018 at 4 pediatric departments. We included girls aged 6-14 years and boys aged 9-17 years evaluated as having puberty onset and excluded those with precocious puberty diagnosis. The anthropometric measures were collected every 3 months. The main outcome was age at puberty onset. Data were analyzed between July 2018 and September 2020.

RESULTS

For 153 girls and 83 boys, BFP was significantly related to puberty onset for girls. Longitudinal analysis revealed that BFP in the girls was reduced to less than 18% 6 months before puberty and rapidly increased by 2.85% over 3 months, then exceeding 20% before puberty onset. After puberty onset, BFP was no longer lower than 22%.

CONCLUSIONS

BFP is an essential predictor of age at puberty onset. BFP first decreases and then begins to increase 3-6 months before puberty in girls. Parents and schools could monitor the BFP of prepubescent girls every 6 months to predict puberty onset.

[Arf6 regulates endometriotic epithelial-mesenchymal transition and mitochondrial distribution]

Objective: To investigate the role of adenosine diphosphate ribosylation factor 6 (Arf6) in the pathogenesis of endometriosis. Methods: Endometrial tissues were sampled from women who were hospitalized in the Affiliated Hospital of Medical School of Ningbo University and Ningbo Women and Children's Hospital from November 2020 to May 2021 with endometriosis (n=44, endometriosis group) and without endometriosis (n=17, control group). The expression of Arf6 protein in the endometrial tissues was detected by western blot. Endometrial epithelial cells from both groups were primary cultured and the distribution of intracellular mitochondria was detected by immunofluorescence. The expression of Arf6 protein was down-regulated by small interference RNA (siRNA), the distribution of mitochondria in cells with decreased Arf6 protein expression was observed, and the expression of mitochondria-related proteins development and differentiation enhancing factor 1 (DDEF1, also called AMAP1), reactive oxygen species 1 (ROS1) and epithelial-mesenchymal transition (EMT)-related proteins E-cadherin, vimentin were detected. Transwell assay was used to detect the changes in the migration ability of the cells. Results: Compared with the control group, ectopic endometrial tissue of endometriosis group showed high expression of Arf6 protein (0.174±0.019 vs 0.423±0.033; t=29.630, P<0.01); and in ectopic endometrial epithelial cells, mitochondria were distributed near the edge of the cell membrane. While Arf6 expression was down-regulated by siRNA, the distribution of mitochondria in ectopic cells returned to natural, close to the control level. In addition, the expression levels of AMAP1 and ROS1 in ectopic cells after Arf6 protein knockdown were significantly decreased. Transwell assay results indicated that knockdown of Arf6 could reduce the migration ability of ectopic epithelial cells [migration cell count: (34.3±7.5) cells]; and immunofluorescence verified low expression of E-cadherin but high expression of vimentin in ectopic epithelial cells, whereas knockdown of Arf6 protein E-cadherin expression increased but vimentin expression decreased. Conclusions: High expression of Arf6 protein in ectopic endometrial epithelial cells leads to the distribution of mitochondria tending to membrane marginalization, while inducing EMT, which are involved in the mechanism of endoheterosis pathogenesis.

Single-Crystal to Single-Crystal Transformation of a Spin-Crossover Hybrid Perovskite via Thermal-Induced Cyanide Linkage Isomerization

Linkage isomers involving changes in the bonding mode of ambidentate ligands have potential applications in data storage, molecular machines, and motors. However, the observation of the cyanide-linkage-isomerism-induced spin change (CLIISC) effect characterized by single-crystal X-ray diffraction remains a considerable challenge. Meanwhile, the high-spin and low-spin states can be reversibly switched in spin-crossover (SCO) compounds, which provide the potential for applications to data storage, switches, and sensors. Here, a new perovskite-type SCO framework (PPN)[Fe{Ag(CN)₂}₃] (PPN⁺ = bis(trisphenylphosphine)iminium cation) is synthesized, which displays the unprecedented aging and temperature dependences of hysteretic multistep SCO behaviors near room temperature. Moreover, the thermal-induced cyanide linkage isomerization from Fe^II-N≡C-Ag^I to Fe^II-C≡N-Ag^I is revealed by single-crystal X-ray diffraction, Raman, and Mössbauer spectra, which is associated with a transition from the mixed spin state to the low-spin state and a dramatic volume shrinkage. Considering the wide use of cyanogen in magnetic systems, the association of CLIISC and SCO opens a new dimension to modulate the spin state and realize a colossal negative thermal expansion.

[Analysis of adenoid hyperplasia and its influencing factors of neonates]

Objective: To explore the characteristics of neonatal adenoid development and to study the relationship between neonatal adenoid development and disease. Methods: A retrospective analysis of neonates who received an electronic rhinopharyngolaryngoscope at Shenzhen Children's Hospital from January 2019 to December 2020 was conducted to track the children's medical history and to analyze the adenoid development status. All 131 neonates successfully completed the electronic laryngoscopy. According to the presence or absence of visible adenoid hyperplasia, they were divided into a hyperplasia group (81 cases, 61.83%) and an un-hyperplasia group (50 cases, 38.17%). Results: Compared with the un-hyperplasia group, the age and birth weight of the adenoid hyperplasia group were larger, and the difference was statistically significant (Z _age=-4.634,Z _weight=-2.273,all P<0.05), but there was no significant difference in gender and gestational age between the two groups. The number of neonates with rhinitis/sinusitis in the hyperplasia group were significantly more than those in the un-hyperplasia group (62.96% vs 48%). Conclusion: The development of neonatal adenoids is related to daily age, birth weight, but not significantly related to gender and gestational age.

[Clinical effects of en bloc resection and debridement combined with gluteus maximus muscle flap in the treatment of ischial tubercle pressure ulcer complicated with chronic osteomyelitis]

Objective: To investigate the clinical effects of en bloc resection and debridement combined with gluteus maximus muscle flap in the treatment of ischial tubercle pressure ulcer complicated with chronic osteomyelitis. Methods: A retrospective observational study was conducted. From May 2018 to February 2020, 8 patients with pressure ulcers on the ischial tuberosity combined with chronic osteomyelitis who met the inclusion criteria were admitted to Fuyang Minsheng Hospital, including 5 males and 3 females, aged 38-69 years, with unilateral lesions in 6 patients and bilateral lesions in 2 patients. According to the anatomical classification of Cierny-Mader osteomyelitis, there were 6 patients (7 sides) with focal type, and 2 patients (3 sides) with diffuse type. The wound areas were 3 cm×2 cm to 12 cm×9 cm on admission. The pressure ulcer and chronic osteomyelitis lesions were completely removed by en bloc resection and debridement. The chronic infectious lesions were transformed into sterile incisions like fresh wounds by one surgical procedure, and the gluteus maximus muscle flaps with areas of 10 cm×6 cm to 15 cm×9 cm were excised to transfer and fill the ineffective cavity. The wounds of 5 patients were sutured directly, and the wounds of 3 patients were closed by local flap transfer. The intraoperative blood loss volume and blood transfusion, and length of hospital stay of patients were recorded. The incision healing and flap survival of patients were observed after operation. The recurrence of pressure ulcer and osteomyelitis, the appearance of the affected area, and the secondary dysfunction and deformity of the muscle flap donor site of patients were observed during followed up. Results: The intraoperative blood loss volume of the 8 patients was 220 to 900 (430±150) mL; 5 patients received intraoperative blood transfusion, of which 2 patients received 3 U suspended red blood cells and 3 patients received 2 U suspended red blood cells. The length of hospital stay was 18 to 29 (23.5±2.0) d for the 8 patients. In this group of patients, the incisions of 7 patients healed, while in one case, the incision suture was torn off during turning over and healed after secondary suture. The flaps survived well in 3 patients who underwent local flap transfer. During the follow-up period of 6-20 months, no recurrence of pressure ulcer or osteomyelitis occurred in 8 patients, the affected part had skin with good texture, mild pigmentation, and no sinus tract formation, and no secondary dysfunction or deformity occurred in the donor site. Conclusions: The en bloc resection and debridement combined with gluteus maximus muscle flap has good clinical effects on ischial tubercle pressure ulcer complicated with chronic osteomyelitis. Neither pressure ulcer nor osteomyelitis recurs post operation. The skin texture and appearance of the affected area are good, and the donor site has no secondary dysfunction or deformity.

High-precision measurement of the W boson mass with the CDF II detector

The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, M_W, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera-electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain [Formula: see text], the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega-electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.

Opening Magnetic Hysteresis via Improving Planarity of Equatorial Coordination by Hydrogen Bonding

Through a mixed-ligand strategy, the structural change from a discrete dinuclear DyIII cluster to a one-dimensional polymeric chain was achieved, maintaining the two magnetic entities with the same {Dy(dppbO2)2(H2O)5} (dppbO2...

Single-Molecule Magnets beyond a Single Lanthanide Ion: The Art of Coupling

The promising future of storing and processing quantized information at the molecular level has been attracting the study of Single-Molecule Magnets (SMMs) for almost three decades. Although some recent breakthroughs are mainly about the SMMs containing only one lanthanide ion, we believe SMMs can tell a much deeper story than the single-ion anisotropy. Here in this Perspective, we will try to draw a unified picture of SMMs as a delicately coupled spin system between multiple spin centres. The hierarchical couplings will be presented step-by-step, from the intra-atomic hyperfine coupling, to the direct and indirect intra-molecular couplings with neighbouring spin centres, and all the way to the inter-molecular and spin–phonon couplings. Along with the discussions on their distinctive impacts on the energy level structures and thus magnetic behaviours, a promising big picture for further studies is proposed, encouraging the multifaceted developments of molecular magnetism and beyond.

In this Perspective, we draw a unified picture for single-molecule magnets as delicately coupled spin systems, discuss the hierarchical couplings (from intra-atomic to inter-molecular) and their distinctive impacts on the magnetic behaviours.

Magnetization Dynamics on Isotope-Isomorphic Holmium Single-Molecule Magnets

Here we reported the deuteration of the metal-binding equatorial water molecules in a reported Ho^III single-molecule magnet (SMM) with pentagonal-bipyramidal geometry, from [Ho(CyPh₂ PO)₂ (H₂ O)₅ ]³⁺ to [Ho(CyPh₂ PO)₂ (D₂ O)₅ ]³⁺ . The hyperfine structures originating from the nuclear spin of ¹⁶⁵ Ho^III can be clearly observed. Moreover, the resulting magnetization dynamics revealed the switch of the relative relaxation rates for the two isotope-isomorphic complexes-respectively faster/slower at low/high temperature. The noticeable isotope effect arises from not only the paramagnetic metal center but also the diamagnetic ligands, which can be explained by the ab initio calculated tunnel splitting and the involvement of the super-hyperfine interaction related to the difference in the nuclear spin number of protium (¹ H, I=¹ /₂ ) and deuterium (² H, I=1).

[Development of Risk Assessment Index System on HIV infection among young students based on Delphi method]

Objective: To develop a Risk Assessment Index System (RAIS) on HIV infection among young students based on Delphi method and to provide individual HIV infection risk assessment, targeted prevention and control measures. Methods: Delphi method was applied to determine the index system and weight of the assessment tool through three rounds of expert consultation and overall consideration of opinions and suggestions from 19 experts. Results: The positivity coefficients of three rounds of expert consultation were 100%. The authority coefficient of experts was between 0.887 and 0.945. The Kendall's W coefficients through first, second and third round specialist consultation was 0.379, 0.329 and 0.248, respectively (all P<0.001). The coefficients of variation in the third round were all less than 0.25, indicating that experts' opinion tend to be consistent and the results are highly reliable. The HIV infection risk assessment index system among young students consisted of 7 first grade indices and 54 second grade indices, of which weight was calculated. Conclusions: The RAIS on HIV infection for young students was initially established based on Delphi method, and could be used in the development of HIV infection risk assessment tools for personalized prevention and intervention among young students. However, the reliability, validity and effect of this assessment index system need to be further evaluated.

[Design and analysis of testing results of a WeChat applet for sexual health and HIV infection risk assessment in young students]

Objective: To summarize the design and analysis of testing results of a WeChat applet, which is called "Detective Bear", for sexual health and HIV infection risk assessment in young students, and evaluate its feasibility and effectiveness. Methods: Based on self-categorization theory, by using cluster analysis and Delphi expert consulting method, the framework of WeChat applet, risk assessment index system and preventive intervention content were determined. Young students were recruited by student associations for the application test, the results of the repeated tests and the satisfaction survey were collected and analyzed. Results: The study included 393 participants who repeated the test twice and 750 participants who volunteered to participate in the satisfaction questionnaire survey. The applet contains five modules: self-role judgment, self-test, risk assessment, assessment report generation and background management. The risk assessment module contains 6 first-level indicators and 55 second-level indicators. Assessment report generation module includes role diagnosis type, radar chart of HIV sexual health KAP and intervention prescription. In 393 students who repeated the test, the awareness of AIDS to be a serious sexually transmitted disease, the epidemic trend in young students in China, with active seeking HIV testing services and caring the infected improved. The satisfaction survey showed that 75.7% of students (568/750) accepted the applet, 86.5% (649/750) agreed the evaluation report, 83.1%(623/750) thought that there were some problems, but it was easy to use, 93.3% (700/750) said they can learn something from the applet and 84.1% (631/750) satisfied with the page design. Some students thought the questionnaire was too long and somewhat difficult to complete (P<0.05), and some reported that more can be learned (P<0.05). Conclusions: The applet integrates AIDS prevention related knowledge and practice into a challenging, interesting, interactive game and provide individualized, concrete risk assessment and self-intervention for young students, which can effectively help students to improve the awareness of AIDS related knowledge and get links for access to condoms, testing and other intervention services. However, its large-scale application and long-term effect need to be further tested.

[Influence of self-categorized deviation in knowledge, attitude and practice for sexual health on the willingness to seek help for corresponding problems among young students]

Objective: To evaluate the effect of "self-categorization" on decision of health preference and the influence of self-categorized deviation in knowledge, attitude and practice (KAP) on the willingness of seeking help for sexual health among young students. Methods: From March to April 2019, young students who used a WeChat applet for sexual health and HIV infection risk assessment, which is called "Detective Bear" were recruited and investigated. According to the consistency between the self-categorization of KAP for sexual health and the systematic categorization from their honest answers, the participants were allocated into three groups: consistent, low or high status, according to their judgment on sexual information acquisition, sexual attitude, and the actual number of sexual experiences. Logistic regression was used to analyze the differences in the willingness to seek help for sexual health problems between the three groups. Results: 2 009 students with an average age of (19.2±1.1) were included. 54.7% (1 099/2 009) were female, and 98.4% (1 976/2 009) were college, undergraduate or postgraduate students. 49.0% (984/2 009) were in the consistent group, 10.9% (219/2 009) had a lower self-categorization, 40.1% (806/2 009) had a higher self-categorization. Compared with the consistent group, students with lower self-categorization of KAP for sexual health were less likely to assess HIV voluntary counseling and testing (aOR=0.65, 95%CI: 0.43-0.99). However, students with higher self-categorization seemed to dislike seeking help for sexually transmitted diseases (aOR=0.76, 95%CI: 0.59-0.98). Conclusions: Deviation in self-categorization of KAP for sexual health will reduce the young students' willingness to seek help for related problems. Especially those with lower self-categorization, lack of risk consciousness, and refuse to assess counseling and testing may increase the HIV/AIDS epidemic among this population. It is necessary to strengthen the capacity of self-assessment for young students while promoting sex education.

[Analysis on influencing factors of HIV testing services utilization in students with self-assessed high risk of HIV infection based on Andersen's model]

Objective: To analyze the influencing factors for HIV testing services utilization in students with self-assessed high risk of HIV infection. Methods: The research framework of the influencing factors for HIV testing services utilization in students was developed based on Andersen's health services utilization behavioral model and related literature. A cross-sectional survey was performed in students with self-assessed high risk of HIV infection by an online HIV infection risk assessment tool from March to April 2019. Multiple logistic regressions were applied with hierarchical model. Results: A total of 526 students were included in the study (age: 19.30±1.19 years old), in whom 96.2% agreed that HIV testing should be received after high-risk behavior. 56.7% (298/526) had sexual behavior and the HIV testing rate was 11.0% (58/526). The HIV testing rates in students who had and had no sex behavior were 13.42%(40/298) and 7.89% (18/228), respectively. According to the results from multivariate logistic regression analysis, non-heterosexual (compared with heterosexual, OR=7.88, 95%CI: 3.98-15.61) and higher score of AIDS knowledge awareness (compared with lower score, OR=2.05, 95%CI: 1.07-3.93) in propensity factor module, and having risk sexual behavior (compared with having no risk sexual behavior, OR=2.66, 95%CI: 1.41-5.03) and having diagnosis of STD infection in hospital (compared with having no such diagnosis, OR=6.35, 95%CI: 2.21-18.27) in demand factor module, and receiving health education about AIDS prevention in the past year (compared with receiving no such health education, OR=0.29, 95%CI: 0.11-0.76) and receiving health education about AIDS testing service in the past year (compared with receiving no such health education, OR=3.67, 95%CI: 1.71-7.90) in ability factor module were the influencing factors for utilization of HIV testing services. Conclusions: The acceptance of HIV testing in students needs to be improved urgently. Propensity factors, such as their AIDS knowledge awareness and sexual orientation, and demand factors, such as having risk sexual behavior and STD infection, have obvious impacts on the utilization of HIV testing services. However, health education about AIDS prevention and HIV testing service can play a more important role in facilitating the utilization of HIV testing in students. In the future, we should further strengthen the publicity of voluntary HIV counseling and testing service in students with particular attention to girls and those with risk sexual behaviors.

[Cluster analysis on survey of sexual health characteristics and health education demands in young students]

Objective: To explore the difference of sexual health characteristics and demands in students in different groups, and provide the basis for targeted sexual health eduction for AIDS prevention in young students. Methods: A survey was conducted based on the requirement of health education about sexual health and AIDS prevention in young students by the education department of Guangdong province. A two-step cluster analysis was performed on the survey data obtained by convenient sampling, the variables and number of clusters included were determined by combination of analysis results and professional knowledge. The demographic characteristics, the content and form of sexual health education needed were compared among different groups. Results: Survey data of 3 884 students were collected, and six variables were used for classification: cognition or occurrence masturbation, sexual behavior, frequency of sexual information acquisition, number of acceptable sex partners and AIDS knowledge awareness rate. By these variables, the students were classified into three levels of risk groups: high risk group (46.6%), medium risk group (39.9%) and low risk group (13.5%). As for demographic characteristics, high risk group, with a median age of 19 years, had the highest proportions of boys (65.9%), students with non-heterosexuality orientation (15.2%), urban residents (58.2%), only children (30.8%) and undergraduates (54.7%). Medium risk group, with a median age of 19 years, had the highest proportions of girls (82.7%) and vocational college students (34.0%). Low risk group, with a median age of 18 years, had the highest proportions of rural residents (52.4%), non-only child (80.6%), senior high school students (41.3%), non-boarding students (17.5%) and students without internship and part-time job experience (43.2%). In terms of health education demands, high risk group had a higher demand of information about self-identity, sexual safety, sexual decision making, contraception, abortion, and sexually transmitted disease or AIDS prevention. Medium risk group paid more attention to value on love and marriage, sexual assault. Low risk group showed a higher demand of adolescent physiology knowledge. Compared with low risk group, high risk group had a higher demand of peer education, Internet/multimedia, anonymous counseling and other forms of sexual health education. The differences were significant. Conclusion: The characteristics, sexual knowledge awareness, attitude and behavior, and health education demands of young students in different groups are different, so health education materials and methods should be developed according to the characteristics of different groups to enhance the acceptance and enthusiasm of students and improve the quality of sexual health education.

[Association of coronary perivascular fat attenuation index, the parameters of plaque and fractional flow reserve]

Objective: To explore the association of coronary perivascular fat attenuation index (FAI), the parameters of plaque and fractional flow reserve (FFR). Methods: A total of 113 patients (with 141 plaques) (78 males and 35 females, age from 40 to 83 years) with stable coronary artery disease were retrospectively collected from Jingling Hospital and Shanghai Sixth People's Hospital. All the patients underwent coronary CT angiography and invasive FFR examinations. The quantitative and qualitative parameters of plaque and vessel (such as the length and volume of plaque, the characteristics of plaque and high-risk plaque) and the FAI around the plaque were measured. The patients were divided into positive FAI group (n=46) and negative FAI group (n=66) according to the standard of whether the threshold of FAI≥ -70 HU. The quantitative indexes, including age, the length and volume of plaque, minimal lumen area (MLA) and FAI, as well as the qualitative indexed, including the characteristics of plaque, the number and characteristic of high-risk plaque and the number of patients and plaque with positive FFR were compared between the two groups. Further, logistic regression analysis was performed to analyze the correlation among myocardial ischemia, age, the length of plaque, minimal lumen area (MLA), FAI and so on. ROC curve was used for evaluating the performance of each parameter. Results: Compared to the negative FAI group, positive FAI group had lower MLA (2.00±1.33 mm² vs 4.13±2.41 mm², P<0.001). The proportion of patients and vessels with FFR<0.75 in positive FAI group were significantly higher than that in negative FAI group (21.3% vs 4.5%, P=0.006; 23.2% vs 8.2%, P=0.016). The FAI between high-risk plaque and non-high-risk plaque had no significant difference (21.2% vs 16.1%, P=0.451). FAI predicted myocardial ischemia (AUC=0.666, P=0.021) and significantly improved the prediction efficiency of complex model(0.915 vs 0.951,P=0.033). Conclusion: Lower MLA and higher incidence of myocardial ischemia were associated with patients with higher FAI. In addition, FAI has a certain prediction efficiency and can provide incremental value for the determination of myocardial ischemia.

Guest-Driven Light-Induced Spin Change in an Azobenzene Loaded Metal-Organic Framework

Stimuli-responsive materials that can be reversibly switched by light are of immense interest. Among them, photo-responsive spin crossover (SCO) complexes have great promises to combine the photoactive inputs with multifaceted outputs into switchable materials and devices. However, the reversible control the spin-state change by photochromic guests is still challenging. Herein, we report an unprecedented guest-driven light-induced spin change (GD-LISC) in a Hofmann-type metal-organic framework (MOF), [Fe(bpn){Ag(CN)₂ }₂ ]⋅azobenzene. (1, bpn=1,4-bis(4-pyridyl)naphthalene). The reversible trans-cis photoisomerization of azobenzene guest upon UV/Vis irradiation in the solid-state results in the remarkable magnetic changes in a wide temperature range of 10-180 K. This finding not only establishes a new switching mechanism for SCO complexes, but also paves the way toward the development of new generation of photo-responsive magnetic materials.

[Resting-state functional magnetic resonance imaging analysis of abnormal directional functional connectivity of the nucleus accumbens in patients with chronic tinnitus]

Objective: To investigate abnormal directional functional connectivity of the nucleus accumbens (NAc) in chronic tinnitus patients using resting-state functional magnetic resonance imaging (fMRI), and to determine the relationship between the degree of this connectivity and tinnitus characteristics. Methods: The resting-state fMRI data of 40 patients with bilateral chronic tinnitus (12 males and 28 females, aged from 26 to 63(50.6±11.6) years) and 40 healthy controls with normal hearing (16 males and 24 females, aged from 26 to 70(45.9±12.4)years) were retrospectively enrolled from the Department of Otolaryngology, Nanjing First Hospital from January 2017 to January 2020. The bilateral NAc were selected as seeds to detect the directional functional connectivity with the whole brain, then the effective connectivity values between the two groups were compared using Granger Causality Analysis (GCA), and the correlation between the effective connectivity and the characteristics of tinnitus was calculated. Results: Compared with healthy controls, the effective connectivity from the left NAc to left middle frontal gyrus in patients with bilateral chronic tinnitus was increased [(1.0±0.2)vs(0.6±0.3)], the effective connectivity from the right NAc to left inferior frontal gyrus was enhanced [(0.9±0.3)vs(0.6±0.4)], the effective connectivity from the right middle temporal gyrus to left NAc was enhanced [(1.0±0.2)vs(0.5±0.3)], the effective connectivity from the right middle frontal gyrus to right NAc was also enhanced[(1.0±0.2)vs(0.5±0.3)](all P<0.05). After adjusting for age, gender, education level, and gray matter volume, positive correlations was observed between the Tinnitus Handicap Questionnaire (THQ) scores and increased effective connectivity values from the left NAc to the left middle frontal gyrus (r=0.386, P=0.020). Additionally, enhanced effective connectivity values from the right middle frontal gyrus to the right NAc was also positively associated with tinnitus duration (r=0.390, P=0.019). Conclusion: The directional functional connectivity between the NAc and prefrontal cortex in patients with chronic tinnitus is enhanced.

The production of single cell protein from biogas slurry with high ammonia-nitrogen content by screened Nectaromyces rattus

In this study, a novel method was proposed to obtain single cell protein (SCP) in yeast by using biogas slurry as culture medium. The results show that Nectaromyces rattus was the most efficient at producing SCP among the 7 different yeasts studied. Acetic acid was a better pH regulator than hydrochloric acid. After culture with the initial NH₄⁺-N concentration 2,000 mg/L, C/N ratio 6:1, the initial pH 5.50 and rotation speed of 200 rpm, a total cell dry weight of 12.58 g/L with 35.96% protein content was obtained. Nineteen amino acids accounted for 46.85% of cell dry weight, and proline content was as high as 12.0% of the cell dry weight. However, sulfur-containing amino acids, including methionine and cystine, were deficient. Further research should focus on the high cell density culture to increase SCP production.

Forensic Analysis of 43 Medical Disputes Caused by Death after Cardiac Surgery

Abstract

Objective To explore the causes and characteristics of medical disputes caused by death after cardiac surgery and to analyze the pathological changes after cardiac surgery and the key points of forensic anatomy, thus to provide pathological evidence for clinical diagnosis and treatment of cardiac surgery and judicial appraisal as well as reference for the prevention of medical disputes in such cases. Methods Forensic pathological cases of medical disputes caused by death after cardiac surgery which were accepted by the Center for Medicolegal Expertise of Sun Yat-Sen University from 2013 to 2018 were analyzed retrospectively from aspects such as causes of death, pathological diagnosis, surgery condition, medical misconduct, and so on. Results The causes of death after cardiac surgery of 43 patients were abnormal operation, low cardiac output syndrome, postoperative infection, postoperative thrombosis, and other diseases. Among the 43 cases, there were 18 cases without medical fault while 25 cases had medical fault. Conclusion The medical disputes caused by death after cardiac surgery are closely related to the operative technique and postoperative complications. The causes of medical faults include defects in diagnosis and treatment technique, as well as unfulfillment of duty of care.

Opening Magnetic Hysteresis by Axial Ferromagnetic Coupling: From Mono-Decker to Double-Decker Metallacrown

Combining Ising-type magnetic anisotropy with collinear magnetic interactions in single-molecule magnets (SMMs) is a significant synthetic challenge. Herein we report a Dy[15-MC_Cu -5] (1-Dy) SMM, where a Dy^III ion is held in a central pseudo-D_5h pocket of a rigid and planar Cu₅ metallacrown (MC). Linking two Dy[15-MC_Cu -5] units with a single hydroxide bridge yields the double-decker {Dy[15-MC_Cu -5]}₂ (2-Dy) SMM where the anisotropy axes of the two Dy^III ions are nearly collinear, resulting in magnetic relaxation times for 2-Dy that are approximately 200 000 times slower at 2 K than for 1-Dy in zero external field. Whereas 1-Dy and the Y^III -diluted Dy@2-Y analogue do not show remanence in magnetic hysteresis experiments, the hysteresis data for 2-Dy remain open up to 6 K without a sudden drop at zero field. In conjunction with theoretical calculations, these results demonstrate that the axial ferromagnetic Dy-Dy coupling suppresses fast quantum tunneling of magnetization (QTM). The relaxation profiles of both complexes curiously exhibit three distinct exponential regimes, and hold the largest effective energy barriers for any reported d-f SMMs up to 625 cm^-1 .

Sensitive magnetic-field-response magnetization dynamics in a one-dimensional dysprosium coordination polymer

A Dy(iii) coordination polymer shows significant single-molecule magnet behavior with a sensitive low-field response.

[Mechanism of maggot debridement therapy in promoting wound angiogenesis in patients with diabetic foot ulcer]

Objective: To investigate the mechanism of maggot debridement therapy (MDT) in promoting wound angiogenesis in patients with diabetic foot ulcer (DFU). Methods: (1) From June 2018 to June 2019, the patients admitted to Nanjing Junxie Hospital who met the inclusion criteria were recruited, including 12 DFU patients given MDT for three days [6 males and 6 females, aged (56±12) years] and 12 acute trauma patients without diabetes mellitus [6 males and 6 females, aged (53±10) years], who were enrolled into DFU group and non-diabetic trauma group respectively. Before and after application of MDT, the wound characteristics of patients in DFU group were observed and the wound tissue samples were taken. The wound tissue in non-diabetic trauma group was taken at patient's first visit before debridement. The expression of angiogenesis marker CD31 in the wound tissue of patients in DFU group was detected by immunohistochemistry before and after application of MDT. Western blotting and real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-PCR) were used respectively to detect the protein and mRNA expressions of fatty acid synthase (FAS) in wound tissue of patients in DFU group before and after application of MDT and in non-diabetic trauma group before debridement. (2) Human umbilical vein endothelial cells (HUVECs) were cultured in endothelial cell culture medium containing 10% fetal bovine serum. The 3rd to 6th passages of cells in logarithmic growth phase were used in the following experiments. Excretions/secretions (ES) were extracted from 3-day-old sterile Lucilia sericata larvae for subsequent experiments. Three batches of cells were divided into phosphate buffer solution (PBS) control group, high glucose alone group, high glucose+ 5 μg/mL maggot ES group, and high glucose+ 10 μg/mL maggot ES group, which were treated with PBS, glucose in final molarity concentration of 20 mmol/L, glucose in final molarity concentration of 20 mmol/L+ maggot ES in final mass concentration of 5 μg/mL, and glucose in final molarity concentration of 20 mmol/L+ maggot ES in final mass concentration of 10 μg/mL respectively. The total volume of reagents in each group was the same. After 48 hours of culture, Western blotting, real-time fluorescent quantitative RT-PCR and immunofluorescence method were used to detect the protein and mRNA expressions of FAS in each batch of cells and the expression and localization of FAS protein in cells respectively. The number of samples for mRNA expression was 3. (3) Two batches of cells were divided into small interference RNA (siRNA) alone group, siRNA control+ maggot ES group and siRNA-FAS+ maggot ES group, which were transfected with 100 μmol/L (final molarity concentration) insignificant control siRNA, insignificant control siRNA, and siRNA-FAS for 4-6 h respectively, and then they were routinely cultured for 24 h with PBS added, maggot ES in final mass concentration of 10 μg/mL, and maggot ES in final mass concentration of 10 μg/mL respectively. The total volume of reagents in each group was the same. One batch of cells was used for scratch test, the scratch width was observed at 24 hour after scratching to detect the cell migration ability; one batch of cells was subjected to tube forming experiment, and the formation of cell tubules was observed after 24 hours of culture. The number of samples was 3 in scratch test and tube forming experiments. Data were statistically analyzed with t test, one-way analysis of variance, least significant difference test, analysis of variance for repeated measurement, and Bonferroni method. Results: (1) Compared with those before application of MDT, fresh granulation tissue significantly increased and necrotic tissue decreased obviously in wound, and the expression of CD31 significantly increased in wound tissue of patients in DFU group after application of MDT. The expression of FAS protein in wound tissue of patients in DFU group before application of MDT was significantly lower than that in non-diabetic trauma group before debridement, and the expression of FAS protein in wound tissue of patients in DFU group after application of MDT was significantly higher than that before application of MDT. The expression of FAS mRNA in wound tissue of patients in DFU group before application of MDT was 1.00±0.17, which was significantly less than 3.87±1.02 in non-diabetic trauma group before debridement (t=9.808, P<0.01). The expression of FAS mRNA in wound tissue of patients in DFU group after application of MDT was 1.85±0.31, which was significantly higher than that before application of MDT (t=-10.853, P<0.01). (2) After 48 hours of culture, Western blotting detection showed that the expression of FAS protein in cells in high glucose alone group was significantly less than that in PBS control group, and the expressions of FAS protein in cells in high glucose+ 5 μg/mL maggot ES group and high glucose+ 10 μg/mL maggot ES group were significantly higher than the expression in high glucose alone group. Real-time fluorescent quantitative RT-PCR determination showed that the expression of FAS mRNA in cells in high glucose alone group was 0.392±0.073, which was significantly lower than 1.000±0.085 in PBS control group (P<0.01); there was statistically significant difference between the expression of FAS mRNA in cells in high glucose+ 5 μg/mL maggot ES group (0.561±0.047) and that in high glucose+ 10 μg/mL maggot ES group (0.687±0.013) (P<0.05), both of which were significantly higher than the expression in high glucose alone group (P<0.01). The results of immunofluorescence detection showed that FAS protein was mainly located in the cytoplasm of cells in each group, and its expression was similar to that detected by Western blotting. (3) At 24 hour after scratch, the uncured widths of cell scratch in siRNA control+ maggot ES group and siRNA-FAS+ maggot ES group were significantly narrower than the uncured width in siRNA alone control group (P<0.01), and the uncured width of cell scratch in siRNA-FAS+ maggot ES group was significantly wider than that in siRNA control+ maggot ES group (P<0.01). After 24 hours of culture, the numbers of tubules in siRNA+ maggot ES group and siRNA-FAS+ maggot ES group were significantly more than the number in siRNA alone control group (P<0.05 or P<0.01), and the number of tubules in siRNA-FAS+ maggot ES group was obviously less than that in siRNA control+ maggot ES group (P<0.05). Conclusions: MDT up-regulates the expression of FAS through maggot ES, which promotes the activity of vascular endothelial cells, thus promoting the wound angiogenesis in patients with DFU.

Magnetic dynamics of an open-ring tridysprosium complex employing mixed ligands

By employing mixed ligands, a new trinuclear dysprosium complex [Dy3(dbm)3(L)4](ClO4)2·CH2Cl2·2MeOH (1, Hdbm = dibenzoylmethane; HL = 2-methoxy-6-((quinolin-8-ylimino)methyl)phenol) was synthesized by a one-pot reaction. According to structural characterization, all the 8-coordinated Dy(iii) sites are well arranged with slightly distorted square antiprism (D4d) geometries. Magnetic measurements reveal that 1 exhibits typical single-molecule magnetic behavior at zero magnetic field and shows rarely open hysteresis loops up to 3 K among open-ring {Dy3} SMMs, where the relaxation time remains very stable under the protection from the Dy-Dy magnetic coupling in the open-ring arrangement of Ising spins.

[Novel coronavirus pneumonia (COVID-19) CT distribution and sign features]

Objective: To investigate the imaging findings of 2019 novel coronavirus pneumonia (COVID-19). Methods: From January 20 to February 5, 2020, a total of 130 patients diagnosed with COVID-19 from seven hospitals in China were collected. The imaging data were reviewed and analyzed in detail. Results: (1) Distribution: the lesion detected in the lung unilaterally in 14 cases (10.7%) and bilaterally in 116 cases (89.3%). According to the distribution in the lobes of the lung, all cases could be classified into subpleural distribution (102 cases, 78.4%), centrilobular distribution (99 cases, 76.1%) and diffused distribution (8 cases, 6.1%). (2) Number of lesions: single lesion 9 cases (6.9%); multiple lesions 113 cases (86.9%), diffuse lesions 8 cases (6.1%). (3) Imaging density: 70 cases (53.8%) of ground-glass opacity (GGO), 60 cases (46.2%) of GGO+consolidation. (4) Accompanying signs: 100 cases (76.9%) with vascular thickening, 98 cases (75.3%) with "pleural parallel sign" ; " intralobular septal thickening" in 100 cases (76.9%); "halo sign" in 13 cases (10%); "reversed-halo sign" in 6 cases (4.6%); pleural effusion in 3 cases (2.3%), and pneumatocele in 2 cases (1.5%); no case with pulmonary cavity. Among 35 patients that underwent follow-up CT, 21 patients (60%) improved while 14 (40%) exacerbated. Conclusions: COVID-19 imaging characteristic mainly has subpleural, centrilobular and diffused distribution. The first two distributions can overlap or progress to diffused distribution. In the later period, it was mainly manifested as organizing pneumonia and fibrosis. The most valuable characteristic is the pleural parallel sign.

Dairy cattle with bovine leukaemia virus RNA show significantly increased leukocyte counts

Infection with bovine leukaemia virus (BLV), a retrovirus, causes dysfunction of the immune system and can have a marked economic impact on dairy industries due to decreased milk production and reduced lifespan in affected dairy cattle. The presence of proviral DNA has been the major diagnostic indicator of BLV infection. However in the course of BLV infection, the viral genome can be dormant, without detectable gene expression, resulting in limited impact on infected animals. At present, there is limited knowledge regarding haematological indices in dairy cattle that could indicate activation of the BLV genome and suggest reactivated BLV infection. In this study, BLV infection and BLV genome reactivation were evaluated based on the presence of BLV DNA and BLV env gene transcripts, respectively. BLV RNA transcription was confirmed. Among 93 whole blood samples obtained from asymptomatic dairy cattle, the prevalence of BLV proviral DNA and transcripts was 93.5% (n = 87/93) and 83.9% (n = 78/93), respectively. Between groups with and without BLV, the mean counts of white blood cells and lymphocytes in whole blood were significantly associated with the presence of BLV RNA (P < 0.05), but not with BLV proviral DNA. These results shed light on the activation status of the BLV genome and should be taken into account when evaluating the possible impact of BLV on cattle.

Light- and temperature-assisted spin state annealing: accessing the hidden multistability

Among responsive multistable materials, spin crossover (SCO) systems are of particular interest for stabilizing multiple spin states with various stimulus inputs and physical outputs. Here, in a 2D Hofmann-type coordination polymer, [Fe(isoq)₂{Au(CN)₂}₂] (isoq = isoquinoline), a medium-temperature annealing process is introduced after light/temperature stimulation, which accesses the hidden multistability of the spin state. With the combined effort of magnetic, crystallographic and Mössbauer spectral investigation, these distinct spin states are identified and the light- and temperature-assisted transition pathways are clarified. Such excitation-relaxation and trapping-relaxation joint mechanisms, as ingenious interplays between the kinetic and thermodynamic effects, uncover hidden possibilities for the discovery of multistable materials and the development of multistate intelligent devices.

Two new two-stage manipulation protocols, namely light- and temperature-assisted spin state annealing (LASSA/TASSA), are applied to a spin crossover coordination polymer, [Fe(isoq)₂{Au(CN)₂}₂], revealing the hidden multistability of spin states.

[Correlation analysis between Dx-pH monitoring and proton pump inhibitor test in the diagnosis of laryngopharyngeal reflux disease]

Objective: The consistency of 24-hour oropharyngeal Dx-pH monitoring and proton pump inhibitor(PPI) test in the diagnosis of laryngopharyngeal reflux disease (LPRD) was investigated. Methods: Sixty patients with laryngopharyngeal reflux (LPR) related symptoms who had never received PPI treatment were assessed by reflux symptom index (RSI) and reflux finding score (RFS) between October 2017 and October 2018, including 28 males and 38 females, aged from 16 to 72 years, with a medium age of 38 years. Prior to treatment, all patients were evaluated with 24 hours oropharyngeal Dx-pH monitoring(Restech). After empiric therapy with PPI twice-daily for 8 weeks, the efficacy was evaluated according to posttreatment RSI score.The data was analysed with Kruskal-Wallis test, Student Newman Keuls test and consistency check. Results: (1)Among all 60 patients,13 patients (21.7%) had pathologic Ryan score and all resulted responsive to PPI;27 patients (45.0%) with a negative Ryan score were unresponsive to PPI; 20 patients (33.3%) despite a negative Ryan score resulted responsive to PPI therapy. Considering responsiveness to PPI therapy as the gold standard for the diagnosis of LPRD, the sensitivity, specificity, positive predictive value and negative predictive value of Ryan score were 39.4%, 100%, 100% and 57.4% respectively. The Kappa value was 0.369 (P<0.01). (2)Among 34 patients (56.7%) with positive Dx-pH results (24-hour oropharyngeal acid reflux events≥ 3 times), 29 patients were positive and 5 patients were negative in PPI test. Among 26 patients with negative Dx-pH results (24-hour oropharyngeal acid reflux events<3 times), 4 patients were positive and 22 patients were negative in PPI test. Considering responsiveness to PPI therapy as the gold standard for the diagnosis of LPRD, the sensitivity, specificity, positive predictive value and negative predictive value of 24-hour oropharyngeal acid reflux events were 87.9%, 81.5%, 85.3% and 84.6% respectively. The Kappa value was 0.696(P<0.01). Conclusions: There is a positive correlation between 24-hour oropharyngeal Dx-pH monitoring positive results (24-hour oropharyngeal acid reflux events≥3 times) and PPI test in the diagnosis of LPRD. The 24-hour oropharyngeal Dx-pH monitoring can be a promising tool for the diagnosis of suspected LPRD patients, and more sensitive and accurate Dx-pH diagnostic index will be required in the clinic.

Physical stimulus and chemical modulations of bistable molecular magnetic materials

In this Feature Article, we summarize the recent progress made in modulating the multifaceted magnetic behaviour of single-molecule magnets (SMMs) and spin-crossover (SCO) materials based on chemical modifications and external stimuli.

Asymmetric seven-/eight-step spin-crossover in a three-dimensional Hofmann-type metal–organic framework

An unprecedented hysteretic seven-/eight-step spin-crossover behavior is revealed. Most importantly, a molecular alloy based on a Hofmann-type framework is used as a strategy to explore multi-step spin-crossover materials for the first time.

A perfect triangular dysprosium single-molecule magnet with virtually antiparallel Ising-like anisotropy

A perfect triangular Dy₃ single-molecule magnet was reported. Each Dy(iii) magnetic axis is oriented almost normal to the plane of Dy₃, and the intramolecular magnetic dipole interaction gives rise to a virtually antiparallel Ising-like ground state.

Spin-crossover in an organic–inorganic hybrid perovskite

The first spin-crossover complex with an organic–inorganic hybrid perovskite structure is reported, which displays three-step spin-crossover, light-induced excited spin-state trapping and spin-state dependent fluorescence properties.

[Value of dual-energy CT-based volumetric iodine-uptake in the evaluation of chemotherapy efficacy in advanced gastric cancer]

Objective: To explore the value of dual-energy CT-based volumetric iodine-uptake (VIU) in the evaluation of chemotherapy efficacy in advanced gastric cancer. Methods: Inclusion criteria of subjects: (1) without previous systematic therapy; (2) with complete clinical information before and after chemotherapy; (3) without contraindications of chemotherapy. Exclusion criteria of subjects: (1) unfinished duration and times of chemotherapy; (2) unmeasurable primary lesions; (3) poor imaging quality or poor gastric filling. Clinical and image data of 52 patients with advanced gastric cancer who were diagnosed by pathology from gastroscopic biopsy, and needed chemotherapy evaluated by imaging and clinical information in the First Affiliated Hospital of Wenzhou Medical University from February 2017 to February 2018 were collected and analyzed. Of 52 patients, 38 were male and 14 were female with the median age of 65 (31-88) years old. All the patients underwent a dual-energy, dual phase-enhanced CT scanning before chemotherapy and after the third chemotherapy session. The parameters of the lesions measured before and after chemotherapy in portal vein phase were as follows: the maximum diameter (the largest diameter among those measured in the cross-sectional, coronal, and sagittal planes), average CT value (the regions of interest were manually pinpointed under cross-sectional planes with largest diameter of the tumor, which did not include regions less than 2 mm to the edge of the tumor) and VIU (lesion volume × iodine concentration). The change rates of maximum lesion diameter, average CT value and VIU before and after chemotherapy were calculated [(post-chemotherapy parameters-pre-chemotherapy parameters)/ pre-chemotherapy parameters]. The efficacy of chemotherapy was evaluated by RECIST 1.1 (the change of maximum tumor diameter after chemotherapy), Choi (the change of average CT value after chemotherapy) and VIU (the change of VIU after chemotherapy), respectively, which was categorized by complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). Patients with CR, PR, and SD were assigned to the effective group, while those with PD were classified as the ineffective group. Paired t - test or Wilcoxon signed ranks test was used to compare the changes of parameters before and after chemotherapy, whereas Spearman correlation analysis and Kappa test were used for the correlation analysis and the consistency test between the three evaluation criteria (Kappa≥0.75 indicated good consistency). Results: After chemotherapy, the average CT value [(74.01±16.75) HU vs. (81.06±15.87) HU, t=2.202, P=0.030] and median VIU (668.53×10(2) μg vs. 272.52×10(2) μg, Z=4.761, P<0.001) decreased significantly, while the difference of the maximum diameter was not statistically significant [(66.71±34.49) mm vs. (78.45±35.62) mm, t=1.708, P=0.091]. The median change rate of VIU (-53.33%) was greater than that of CT values (-5.75%) with significant difference (Z=-5.408, P<0.001). According to the RECIST 1.1 criteria, 47 patients (90.4%, including 19 with PR and 28 with SD) were effective and 5 patients (9.6%) were ineffective. According to the Choi criteria, 45 patients (86.5%, including 37 with PR and 8 with SD) were effective and 7 patients (13.5%) were ineffective. According to the VIU criteria, 46 patients (88.5%, including 41 with PR and 5 with SD) were effective and 6 patients (11.5%) were ineffective. Efficacy comparison among these three criteria showed no significant difference (χ(2)=0.377, P=0.828). As compared to RECIST 1.1 evaluation, the proportion of PR evaluated by Choi and VIU was significantly higher (χ(2)=16.861, P<0.001), whereas the proportion of SD was significantly lower (χ(2)=24.089, P<0.001). There was no significant difference in the proportions of PR and SD between VIU and Choi criteria (χ(2)=0.887, P=0.346). Consistency and correlation analysis showed that the VIU and Choi evaluation criteria presented the highest consistency and correlation (Kappa=0.912, P<0.001; r=0.916, P<0.001). Conclusion: VIU is a feasible parameter for the evaluation of chemotherapy efficacy in advanced gastric cancer, and may be more sensitive than the evaluation criteria based on maximum diameter or change of CT value in the tumor.