Association of improved overall survival with decreased distant metastasis following asparaginase-based chemotherapy and radiotherapy for intermediate- and high-risk early-stage extranodal nasal-type NK/T-cell lymphoma: a CLCG study

BACKGROUND

This study evaluated the survival benefit of asparaginase (ASP)-based versus non-ASP-based chemotherapy combined with radiotherapy in a real-world cohort of patients with early-stage extranodal nasal-type natural killer/T-cell lymphoma (ENKTCL).

PATIENTS AND METHODS

We identified 376 patients who received combined radiotherapy with either ASP-based (ASP, platinum, and gemcitabine; n = 286) or non-ASP-based (platinum and gemcitabine; n = 90) regimens. The patients were stratified into low-, intermediate-, and high-risk groups using the early stage-adjusted nomogram-revised risk index. Overall survival (OS) and distant metastasis (DM)-free survival (DMFS) between the chemotherapy regimens were compared using inverse probability of treatment weighting (IPTW) and multivariable analyses.

RESULTS

ASP-based (versus non-ASP-based) regimens significantly improved 5-year OS (84.5% versus 73.2%, P = 0.021) and DMFS (84.4% versus 74.5%, P = 0.014) for intermediate- and high-risk patients, but not for low-risk patients in the setting of radiotherapy. Moreover, ASP-based regimens decreased DM, with a 5-year cumulative DM rate of 14.9% for ASP-based regimens compared with 25.1% (P = 0.014) for non-ASP-based regimens. The survival benefit of ASP-based chemotherapy and radiotherapy remained consistent after adjusting the confounding variables using IPTW and multivariate analyses; additional sensitivity analyses confirmed these results.

CONCLUSIONS

The findings provided support for ASP-based chemotherapy and radiotherapy as a first-line treatment strategy for intermediate- and high-risk early-stage ENKTCL.

Influence of Different Factors on the Accuracy of Digital Impressions of Multiple Implants: An In Vitro Study

PURPOSE

To investigate the effect of implant angulation, non-free-end partial edentulism, and number of scan bodies on the accuracy of digital impressions of multiple implants in partially edentulous arches.

MATERIALS AND METHODS

Four reference models of partially edentulous mandibles with implants (RM1, RM2, RM3, and RM4) representing different intraoral situations were each scanned 10 times by an intraoral scanner. Reference scans were obtained by a laboratory scanner. Test scans were compared with reference scans to obtain the distance deviations (Δd) and angular deviations (Δθ) between scan bodies for trueness assessment. Differences among the repeated test scans of each model were measured and recorded as Δdp and Δθp for precision assessment. The Student t test (α = .05) was used to compare Δd, Δθ, Δdp, and Δθp of different reference models, including RM2 vs RM1 (effect of non-free-end partial edentulism), RM3 vs RM1 (effect of implant angulation), and RM4 vs RM1 (effect of number of scan bodies).

RESULTS

The implant with 17-degree angulation in RM3 showed significantly lower Δd, Δθ, and Δθp compared with the parallel implant in RM1 (Δd: P = .0382, Δθ: P = .0267, Δθp: P = .0417). The RM2 of non-free-end partial edentulism had lower distance and angular deviations than RM1, but without a significant difference. The number of scan bodies had no significant effect on the Δd, Δθ, Δdp, and Δθp of RM4 and RM1.

CONCLUSION

Angulated implants showed better accuracy of digital impressions in partially edentulous arches compared with parallel implants. Non-free-end partial edentulism was attributed to improved accuracy, while the number of scan bodies showed no effect.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Accuracy of full-arch digital implant impressions taken using intraoral scanners and related variables: A systematic review

PURPOSE

To evaluate the accuracy of full-arch digital implant impressions taken using intraoral scanners and analyse the related variables.

MATERIALS AND METHODS

An electronic search of studies on the accuracy of digital implant impressions in fully edentulous arches from 1 January 2012 to 29 February 2020 was conducted in PubMed, EMBASE and the Cochrane Library. Only peer-reviewed experimental or clinical studies written in English were included. Studies assessing the accuracy of restorations, case reports, clinical reports, technical reports and reviews were excluded. The literature screening, article reading and assessment of risk of bias were carried out by two reviewers. The data on the study characteristics, accuracy outcomes and investigated variables were extracted.

RESULTS

After removal of duplicates, a total of 166 studies were identified, of which 42 were initially selected for full-text reading and 30 were included in the final analysis (29 in vitro studies and one in vivo study). The trueness of digital implant impressions ranged from 7.6 to 731.7 μm, and the precision ranged from 15.2 to 204.2 μm. Angular deviations were between 0.13 and 10.01 degrees. Considering 100 μm and 0.4 degrees as clinically acceptable levels of deviation, 18 studies reported linear/distance/3D deviations larger than 100 μm and only two studies reported angular deviations below 0.4 degrees. The effect of interimplant distance/length of the arch scanned/scanning sequence/scanning range/implant position (nine studies), implant angulation (ten studies), implant depth (five studies), implant connection (two studies), operator experience (six studies), scan body type (three studies), intraoral scanner type (six studies), scanning strategy (two studies) and modification technique (three studies) was investigated.

CONCLUSIONS

Based on the results of the included studies, full-arch digital implant impressions taken using intraoral scanners are not sufficiently accurate for clinical application. Accuracy varies greatly with interimplant distance, scan body type, intraoral scanner type and operator experience, whereas implant angulation, implant connections and implant depth have no effect. The effects of scanning strategy and modification technique need further investigation.

Propensity score matching with R: conventional methods and new features

It is increasingly important to accurately and comprehensively estimate the effects of particular clinical treatments. Although randomization is the current gold standard, randomized controlled trials (RCTs) are often limited in practice due to ethical and cost issues. Observational studies have also attracted a great deal of attention as, quite often, large historical datasets are available for these kinds of studies. However, observational studies also have their drawbacks, mainly including the systematic differences in baseline covariates, which relate to outcomes between treatment and control groups that can potentially bias results. Propensity score methods, which are a series of balancing methods in these studies, have become increasingly popular by virtue of the two major advantages of dimension reduction and design separation. Within this approach, propensity score matching (PSM) has been empirically proven, with outstanding performances across observational datasets. While PSM tutorials are available in the literature, there is still room for improvement. Some PSM tutorials provide step-by-step guidance, but only one or two packages have been covered, thereby limiting their scope and practicality. Several articles and books have expounded upon propensity scores in detail, exploring statistical principles and theories; however, the lack of explanations on function usage in programming language has made it difficult for researchers to understand and follow these materials. To this end, this tutorial was developed with a six-step PSM framework, in which we summarize the recent updates and provide step-by-step guidance to the R programming language. This tutorial offers researchers with a broad survey of PSM, ranging from data preprocessing to estimations of propensity scores, and from matching to analyses. We also explain generalized propensity scoring for multiple or continuous treatments, as well as time-dependent PSM. Lastly, we discuss the advantages and disadvantages of propensity score methods.

[Effect of body mass index on the assisted reproductive outcome of frozen-thawed embryo transfer in patients with polycystic ovary syndrome]

Objective: To investigate the effect of body mass index (BMI) on clinical pregnancy and neonatal outcomes in patients with polycystic ovary syndrome (PCOS) during frozen-thawed embryo transfer. Methods: A total of 650 patients with PCOS who received routine in vitro fertilization or intracytoplasmic sperm injection treatment for frozen-thawed embryo transfer from June 2014 to June 2019 in Tianjin Central Hospital of Gynecology Obstetrics were retrospectively analyzed. According to BMI, PCOS patients were divided into group A (18.5≤BMI<23 kg/m², n=253), group B (23≤BMI<25 kg/m², n=167), and group C (BMI≥25 kg/m², n=230). The general information, clinical pregnancy outcomes, pregnancy complications, the incidence of macrosomia and low-birth-weight infants were compared in the three groups, and the influencing factors of neonatal birth weight were analyzed. Results: The embryo implantation rate, clinical pregnancy rate, and ongoing pregnancy rate all showed downward trend with the increase of BMI, but the differences were not statistically significant (all P>0.05). The live birth rate in group C [47.0% (108/230)] was significantly lower than those in groups A and B, with statistical significance (χ²=7.43, P=0.024). The late miscarriage rate was higher in group C [9.4% (13/139)] than in groups A and B (χ²=7.66, P=0.022). The birth rates of macrosomia in groups B [22.2% (16/72)] and group C [21.1% (16/76)] were significantly higher than that in group A, and the difference was statistically significant (χ²=14.15, P=0.001). There was no statistically significant difference in the incidence of gestational diabetes between the three groups (χ²=3.81, P=0.149). The incidence of hypertension disorders complicating pregnancy increased with the increase of BMI, and the difference was not statistically significant (P>0.05). Regression analysis showed that macrosomia was significantly associated with maternal pre-pregnancy BMI and gestational weeks, and the risk of macrosomia increased by 15% (95%CI: 3%-28%) for every increase in maternal BMI. Conclusions: The embryo implantation rate, clinical pregnancy rate, and ongoing pregnancy rate of PCOS patients in frozen-thawed embryo transfer cycles show downward trend with the increase of BMI. Obese patients with PCOS have a significant increase in late miscarriage rate and a significant decrease in live birth rate. The incidence of hypertension disorders complicating pregnancy in PCOS patients in the obese group has an increasing trend, and the birth rate of macrosomia has increased significantly. Therefore, it is recommended that obese women with PCOS lose weight scientifically before pregnancy to improve pregnancy and neonatal outcomes.

[Investigation on occupational hazards in 20 automobile manufacturing enterprises in Shandong Province]

Objective: To investigate the current situation of occupational hazards in automobile manufacturing enterprises in Shandong Province. Methods: From February to May 2019, the convenience sampling method was adopted to conduct on-site occupational health surveys with 20 automobile manufacturing enterprises in Shandong Province as the survey subjects, to detect the occupational hazard factors in the workplaces and individual exposure levels, and to analyze the occupational health check results of operators. Results: There were 13 small-sized, 4 medium-sized and 3 large-sized enterprises among the 20 automobile manufacturing enterprises. The detection results of benzene and toluene in the workplaces met the occupational exposure limits, and the detection results of welding fumes, manganese and its compounds, and xylene exceed the occupational exposure limits. The maximum short-term exposure concentration (C(STE)) of welding fume in the air of workplaces was 24.23 mg/m(3), and the over-standard rate was 11.0% (16/146) . The maximum time-weighted average concentration (C(TWA)) of welding fume of operators is 10.60 mg/m(3), and the over-standard rate was 11.0% (8/73) . The maximum C(STE) of manganese and its compounds in the air of workplaces was 0.879 mg/m(3), and the of manganese and its compounds of operators was 0.175 mg/m(3), and the over-standard rate was 5.7% (4/70) . The maximum xylene C(STE) in the air of workplaces was 230.00 mg/m(3), and the over-standard rate was 3.9% (2/51) . The maximum xylene C(TWA) of operators was 70.40 mg/m(3), the over-standard rate was 3.6% (1/28) . Among the 4775 workers exposed to occupational hazards, 38 (0.80%) were suspected of electric welder's pneumoconiosis, 27 (0.57%) were suspected of manganese poisoning and 31 (0.65%) were suspected of chronic low-concentration benzene and benzene series poisoning. The detection rates of suspected occupational diseases among workers in small and medium-sized enterprises were relatively high, 2.86% (30/1048) and 4.51% (51/1132) respectively. There was a statistically significant difference in the detection rates of suspected occupational diseases among the operators of different scale automobile manufacturers (P<0.05) . Conclusion: The exposure levels of electric welding fumes, manganese and its compounds in welding jobs and xylene exposure levels in spray painting jobsin Shandong Province's automobile manufacturing enterprises are more serious. The supervision and management of occupational hygiene should be strengthened, the working environment should be improved, and the health of welding and painting workers should be protected.

[Clinical and genetic analysis of 5 pediatric patients with hemiplegic migraine presenting as acute encephalopathy]

Objective: To analyze the clinical and genetic characteristics, diagnosis and treatment of hemiplegic migraine (HM) manifested as acute encephalopathy in children, so as to improve the understanding of this disease. Methods: The clinical data of 5 children diagnosed with HM characterized by acute encephalopathy who were admitted to Beijing Children's Hospital affiliated to Capital Medical University from August 2018 to June 2020 were retrospectively analyzed. Results: Among the 5 cases, 3 were males and 2 females with an age of 9.7 (3.9-12.7) years. The age of disease onset was 7.0(2.1-12.7) years. The peak symptoms of 5 children showed encephalopathy such as drowsiness and coma, as well as other clinical manifestations including headache, visual abnormality, hemiplegia, aphasia, convulsions, and fever, etc. The time to reach the peak was on the 2nd-6th day of the course of the disease. Before the onset of the disease 2 cases were found to have mild brain trauma and 2 cases had similar attacks in the past. Brain magnetic resonance imaging (MRI) showed hemispheric or partial cerebral cortex swelling and restricted diffusion of subcortical white matter in all cases, and cerebellar atrophy in 3 cases. All children received symptomatic treatment, and 2 of them were also treated with low-dose corticosteroids in the meantime. Finally all cases recovered clinically from the attack, but one had atrophic changes left in the affected area on brain MRI. Whole exon sequencing revealed variations of CACNA1A gene in all cases, among which 4 were de novo mutations and 1 case inherited from the mother who had migraine without aura. After the diagnosis, the 5 children were treated with long-term flunarizine and followed up for 22(7-29) months by telephone or in the outpatient clinic. Before the last follow-up, none of them showed weakness or encephalopathy, but one still had intermittent headaches and occasional transient right limb numbness. Conclusions: Hemipleg is often accompanied by impaired consciousness in addition to headache, hemiplegia, aphasia, visual abnormality, etc. Most patients recover completely after a short period, while a few recover slowly and may suffer sequelae such as brain atrophy and cognitive impairment and even death. CACNA1A gene variation is the most common genetic variation. Flunarizine could prevent recurrence of severe attack.

The synergistic effect of grain boundary and grain orientation on micro-mechanical properties of austenitic stainless steel

Micro/nano-scale deformation behavior including hardness, elastic modulus, and pop-ins, was studied in a medical austenitic stainless steel followed by post-mortem EBSD characterization. Relatively higher hardness and modulus was observed near {101} and more pop-ins occurred in this orientation at high loading rate. The activation volume (v) obtained from nanoindentation had weak dependence on grain orientation and was ~10-20 b³, indicating that neither diffusional creep processes nor conventional dislocation segments passing through dislocation forests controls plastic deformation in our study. The plastic zone radius (c) and the distance of the indent from the grain boundary (d) were used to describe the effect of grain boundary on the pop-in effect. The ratio of c/d meets amplitude version of Gaussian peak function distribution for a given orientation, whose peak value remains nearly constant for all the orientations.

Evolution of diverse Hall effects during the successive magnetic phase transitions in Mn2.5Fe0.6Sn0.9 Kagome-lattice alloy

Evolution of diverse Hall effects due to successive magnetic transitions has been observed in Mn_2.5Fe_0.6Sn_0.9 by suitable chemical substitution of Fe in Mn_3.1Sn_0.9. This noncollinear antiferromagnetic alloy exhibits a Neel temperature of 325 K. Upon cooling from 325 K, a magnetic phase transition from noncollinear antiferromagnetism to ferromagnetism occurs at 168 K due to the tilting of magnetization towards c axis. Above this temperature, anomalous Hall resistivity ranged from 0.6 to 1.3 μΩ cm has been observed in noncollinear antiferromagnetic state. Below this temperature, a topological Hall effect (THE) starts to appear due to the non-vanishing scalar spin chirality arising from the noncoplanar spin structure. Further decreasing temperature to 132 K, another magnetic transition happens, resulting in the coexistence of ferromagnetism and antiferromagnetism, so that a Hall plateau with large hysteresis below 70 K is yielded. A hysteresis as high as ∼80 kOe is obtained in ρ _xy -H at 15 K. However, the Hall plateau disappears and only anomalous Hall effect (AHE) persists when further decreasing the temperature to 5 K. The present study provides a picture of diverse magneto-transport properties correlated to the variable spin structures driven by magnetic phase transitions.

The identification of alkaloids from the stems of Picrasma quassioides via computer-assisted structure elucidation and quantum chemical calculations

Four new alkaloids (1-4) and one known alkaloid were isolated from the stems of Picrasma quassioides. The structures of these isolated compounds were elucidated by spectroscopic analyses, a combination of computer-assisted structure elucidation software (ACD/Structure Elucidator) and gauge-including atomic orbital (GIAO) calculation of 1 D NMR data. All compounds were evaluated for their cytotoxic activities against hepatocellular carcinoma HepG2 and Hep3B cells. However, they did not show obvious inhibitory activities.[Figure: see text].

[Advance in immunotherapy on biliary tract cancers]

Biliary tract cancers(BTC),including gallbladder cancer and cholangiocarcinoma,has the characteristics of low early diagnosis rate,complex anatomy,insensitivity to radiotherapy and chemotherapy, and poor prognosis.In recent years,immunotherapy as a new method,has made great progress in the treatment of advanced malignant tumors.Immunotherapy is gradually applied in the treatment of BTC,such as inhibitory agents targeting the immune checkpoint receptor pathway,adoptive immunotherapy and tumor vaccines.

Trendelenburg maneuver predicts fluid responsiveness in patients on veno-arterial extracorporeal membrane oxygenation

BACKGROUND

Evaluation of fluid responsiveness during veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support is crucial. The aim of this study was to investigate whether changes in left ventricular outflow tract velocity-time integral (ΔVTI), induced by a Trendelenburg maneuver, could predict fluid responsiveness during VA-ECMO.

METHODS

This prospective study was conducted in patients with VA-ECMO support. The protocol included four sequential steps: (1) baseline-1, a supine position with a 15° upward bed angulation; (2) Trendelenburg maneuver, 15° downward bed angulation; (3) baseline-2, the same position as baseline-1, and (4) fluid challenge, administration of 500 mL gelatin over 15 min without postural change. Hemodynamic parameters were recorded at each step. Fluid responsiveness was defined as ΔVTI of 15% or more, after volume expansion.

RESULTS

From June 2018 to December 2019, 22 patients with VA-ECMO were included, and a total of 39 measurements were performed. Of these, 22 measurements (56%) met fluid responsiveness. The R² of the linear regression was 0.76, between ΔVTIs induced by Trendelenburg maneuver and the fluid challenge. The area under the receiver operating characteristic curve of ΔVTI induced by Trendelenburg maneuver to predict fluid responsiveness was 0.93 [95% confidence interval (CI) 0.81-0.98], with a sensitivity of 82% (95% CI 60-95%), and specificity of 88% (95% CI 64-99%), at a best threshold of 10% (95% CI 6-12%).

CONCLUSIONS

Changes in VTI induced by the Trendelenburg maneuver could effectively predict fluid responsiveness in VA-ECMO patients. Trial registration ClinicalTrials.gov, NCT03553459 (the TEMPLE study). Registered on May 30, 2018.

Axonal mRNA localization and local translation in neurodegenerative disease

The regulation of mRNA localization and local translation play vital roles in the maintenance of cellular structure and function. Many human neurodegenerative diseases, such as fragile X syndrome, amyotrophic lateral sclerosis, Alzheimer's disease, and spinal muscular atrophy, have been characterized by pathological changes in neuronal axons, including abnormal mRNA translation, the loss of protein expression, or abnormal axon transport. Moreover, the same protein and mRNA molecules have been associated with variable functions in different diseases due to differences in their interaction networks. In this review, we briefly examine fragile X syndrome, amyotrophic lateral sclerosis, Alzheimer's disease, and spinal muscular atrophy, with a focus on disease pathogenesis with regard to local mRNA translation and axon transport, suggesting possible treatment directions.

Development and Validation of a Machine-Learning Model for Prediction of Extubation Failure in Intensive Care Units

Background: Extubation failure (EF) can lead to an increased chance of ventilator-associated pneumonia, longer hospital stays, and a higher mortality rate. This study aimed to develop and validate an accurate machine-learning model to predict EF in intensive care units (ICUs). Methods: Patients who underwent extubation in the Medical Information Mart for Intensive Care (MIMIC)-IV database were included. EF was defined as the need for ventilatory support (non-invasive ventilation or reintubation) or death within 48 h following extubation. A machine-learning model called Categorical Boosting (CatBoost) was developed based on 89 clinical and laboratory variables. SHapley Additive exPlanations (SHAP) values were calculated to evaluate feature importance and the recursive feature elimination (RFE) algorithm was used to select key features. Hyperparameter optimization was conducted using an automated machine-learning toolkit (Neural Network Intelligence). The final model was trained based on key features and compared with 10 other models. The model was then prospectively validated in patients enrolled in the Cardiac Surgical ICU of Zhongshan Hospital, Fudan University. In addition, a web-based tool was developed to help clinicians use our model. Results: Of 16,189 patients included in the MIMIC-IV cohort, 2,756 (17.0%) had EF. Nineteen key features were selected using the RFE algorithm, including age, body mass index, stroke, heart rate, respiratory rate, mean arterial pressure, peripheral oxygen saturation, temperature, pH, central venous pressure, tidal volume, positive end-expiratory pressure, mean airway pressure, pressure support ventilation (PSV) level, mechanical ventilation (MV) durations, spontaneous breathing trial success times, urine output, crystalloid amount, and antibiotic types. After hyperparameter optimization, our model had the greatest area under the receiver operating characteristic (AUROC: 0.835) in internal validation. Significant differences in mortality, reintubation rates, and NIV rates were shown between patients with a high predicted risk and those with a low predicted risk. In the prospective validation, the superiority of our model was also observed (AUROC: 0.803). According to the SHAP values, MV duration and PSV level were the most important features for prediction. Conclusions: In conclusion, this study developed and prospectively validated a CatBoost model, which better predicted EF in ICUs than other models.

[Influence of the stiffness of three-dimensionally bioprinted extracellular matrix analogue on the differentiation of bone mesenchymal stem cells into skin appendage cells]

Objective: To observe the influence of the stiffness of three-dimensionally bioprinted extracellular matrix analogue on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into skin appendage cells. Methods: (1) Sodium alginate of 1 g and 4 g gelatin, 3 g sodium alginate and 8 g gelatin were mixed respectively, and the two mixtures were dissolved in 100 mL ultra-pure water respectively to prepare two sodium alginate-gelatin composite hydrogels, named 1A4G hydrogel and 3A8G hydrogel, which were used in the subsequent experiments. The morphology of the two hydrogels at room temperature, after condensation for 15-30 min at 4 ℃ (the same condensation condition below), after condensation and cross-linking with 25 g/L calcium chloride solution (the same cross-linking condition below), and after condensation and three-dimensional printing with a three-dimensional bioprinter (the same three-dimensional printer below) and cross-linking were observed respectively. Young's modulus (stiffness) of the two kinds of hydrogels was measured by Young's modulus tester after condensation and cross-linking (n=3). Two kinds of hydrogels were cross-linked and freeze-dried, and their pore structure was observed by scanning electron microscope. Two hydrogels were cross-linked and freeze-dried, and the porosity was detected by anhydrous ethanol replacement method (n=3). (2) BMSCs were isolated from femur and tibia of 20 C57BL/6 mice (no limitation with sex, born 7 days) and cultured, and the second passage of cells was used for further test. The BMSCs single cell suspension (1.0×10(7) /mL) was mixed with 1A4G hydrogel and 3A8G hydrogel respectively at 1∶9 volume ratio to prepare BMSCs-loaded 1A4G hydrogel and BMSCs-loaded 3A8G hydrogel for three-dimensional printing. One construct was printed with 1 mL cell-loaded hydrogel (the same dosage for printing below). Mesenchymal stem cells (MSCs) specific medium was added after cross-linking, and the printed constructs were divided into 1A4G group and 3A8G group according to the hydrogel. One construct of each group cultured for 7 days was tested with live/dead kit to count the live cells and dead cells in 50-fold field of view. Nine printed constructs from each of the two groups were taken, and BMSCs of nine wells (1.0×10(6) per well) cultured with 2 mL MSCs specific medium were set as two-dimensional culture group. After 1, 3, 5 day (s) of culture, three printed constructs from 1A4G group and 3A8G group respectively and three wells of cells from two-dimensional culture group were taken to detect the absorbance value in culture medium by cell counting kit 8, denoting the cell proliferation activity. (3) BMSCs-loaded 1A4G hydrogel and BMSCs-loaded 3A8G hydrogel of 10 mL respectively were prepared as in experiment (2), which were respectively mixed with 0.5 mL plantar dermis homogenate extracted from 10 C57BL/6 mice of 1 day postnatal with unknown sex, then three-dimensionally printed, cross-linked, cultured with MSCs specific medium for 3 days and then changed to sweat gland specific medium. The printed constructs were divided into 1A4G group and 3A8G group according to their hydrogel. After 7 days of culture with sweat gland specific medium, the expressions of epithelial cell surface markers cytokeratin-5 (CK5) and CK14, sweat gland cell surface markers CK18 and Na(+) /K(+) -ATPase (NKA), and hair follicle cell surface markers CK17 and alkaline phosphatase (ALP) at protein level in cells of printed constructs in the two groups were detected by immunofluorescence method. The expressions of CK5, CK14, CK18, NKA (detecting ATP1a1), CK17, and ALP at mRNA level in cells of printed constructs in the two groups were detected with real-time fluorescent quantitative reverse transcription polymerase chain reaction (n=3). Data were statistically analyzed with independent sample t test, Fisher's exact probability test, analysis of variance for factorial design, and Bonferroni method. Results: (1) Compared with that of 3A8G hydrogel, 1A4G hydrogel had lower viscosity and better fluidity at room temperature. Both kinds of hydrogels were gel-like after condensation, based on which, the shape of cross-linked hydrogels was uniform and regular, with three-dimensional printing and cross-linking made hrdrogels forming solid crisscross cylindrical constructs. The Young's modulus of 1A4G hydrogel was (52±6) kPa, which was obviously lower than (218±5) kPa of 3A8G hydrogel (t=40.470, P<0.01). The pore structure of the two hydrogels was similar, with all the cross-sections showing porous network structure. The porosity of the two hydrogels was similar (t=0.930, P>0.05). (2) The distribution of live/dead cells between 1A4G group and 3A8G group was similar after 7 days of culture (P>0.05), most of which were live cells. The absorbance value in culture medium of printed constructs among 1A4G group, 3A8G group, and two-dimensional culture group didn't show statistically significant differences after 1, 3, 5 day (s) of culture (P>0.05). Compared with that after 1 day of culture within each group, the absorbance value in culture medium of printed constructs in 1A4G group and 3A8G group was significantly increased after 3 and 5 days of culture (P<0.05 or P<0.01), and the absorbance value in culture medium of cells in two-dimensional culture group was significantly increased after 5 days of culture (P<0.01). Compared with that after 3 days of culture within each group, the absorbance value in culture medium of printed constructs in 1A4G group and 3A8G group and that of cells in two-dimensional culture group was significantly increased after 5 days of culture (P<0.01). (3) After 7 days of culture with sweat gland specific medium, the CK5, CK14, CK18, NKA, CK17, and ALP were positively expressed at protein level in cells of printed constructs in the two groups. After 7 days of culture with sweat gland specific medium, the expressions of CK5, CK14, CK18, and NKA at mRNA level in cells of printed constructs were close between the two groups (t=0.362, 0.807, 0.223, 1.356, P>0.05); the expressions of CK17 and ALP at mRNA level in cells of printed constructs in 3A8G group were 1.96±0.21 and 55.57±11.49, respectively, which were significantly higher than 1.05±0.42 and 2.01±0.27 in 1A4G group (t=3.333, 8.074, P<0.05 or P<0.01). Conclusions: BMSCs cultured three-dimensionally in 1A4G and 3A8G hydrogels tend to differentiate into sweat gland cells, but the BMSCs cultured three-dimensionally in 3A8G hydrogel show a stronger tendency to differentiate into hair follicle cells than the cells cultured in 1A4G hydrogel. It suggests that relatively high stiffness of three-dimensionally bioprinted extracellular matrix analogue facilitates not only differentiation of BMSCs into sweat gland cells, but also their differentiation into hair follicle cells.

Application Exploration of Participation Rules in Environmental Damage Identification

Abstract

[Research progress on the occurrence and prevention of low back pain in naval officers and soldiers]

Low back pain (LBP) is a common occupational disease among naval officers and soldiers. This article reviewed the incidence of LBP in naval personnel in different positions in recent years, and analyzed the causes combined with the operating environment and occupational characteristics of personnel in different positions in order to clarify the causes of LBP in naval officers and soldiers in different positions and improve their awareness of the disease. Moreover, this study aims to help naval officers and soldiers to take protective measures in training life to reduce the incidence of LBP.

[Effectiveness and safety of sofosbuvir/velpatasvir combination ± ribavirin in the treatment of Chinese adults with chronic hepatitis C virus infection]

Objective: To understand the effectiveness and safety sofosbuvir/velpatasvir (SOF/VEL) combination ±ribavirin in the treatment of chronic hepatitis C virus (HCV) infection in China. Methods: A total of 96 Chinese adults with chronic HCV infection who were treated with SOF/VEL combination ± ribavirin for 12 weeks between July 2018 and February 2020 were selected. HCV RNA, routine blood test, liver, kidney and coagulation function, abdominal Color Doppler ultrasound or CT and liver stiffness were detected at baseline, 4 weeks of treatment, end of treatment and 12 weeks of follow-up. Adverse events and laboratory abnormalities during the treatment were recorded. A t-test was used to compare the measurement data between the two groups, and the analysis of variance was used for multiple group comparison. Results: A total of 93 cases (96.9%) achieved sustained virological response (SVR12), of which 3 cases had relapsed. 88 cases (91.7%, 88/96) had achieved rapid virological response (RVR). 96 cases (100%) had achieved virological response by the end of treatment (EOT). In patients with decompensated liver cirrhosis, the average baseline Child-Pugh score and Model for End-Stage Liver Disease score was 7.4±1.0, and 11.4±1.7, respectively. Among them, 12 cases of the SOF/VEL combined with RBV treatment had achieved SVR12 (100%) at 12 weeks, while only 3 of the 5 cases of single-tablet regimen of SOF/VEL had achieved SVR12 (60%). There was no significant difference between creatinine levels and baseline during or 12 weeks after treatment. The incidence of adverse events in patients with chronic hepatitis C and compensated cirrhosis was 6.3% (5/79), while that in patients with decompensated cirrhosis was 35.3% (6/17). The most common adverse events were hyperbilirubinemia, fatigue and anemia. There were no serious adverse events, deaths or discontinuation of treatment due to adverse events. Conclusion: SOF/VEL combination ± ribavirin in the treatment of various common genotypes of chronic hepatitis C, compensated cirrhosis, decompensated cirrhosis and hepatocellular carcinoma has higher SVR12 in China, and the tolerance and safety are good.

[Evaluation of drug-drug interactions between yimitasvir phosphate capsules with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets]

Objective: To evaluate the drug-drug interactions and the tolerability of combined medication between yimitasvir phosphate capsules with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets in healthy volunteers. Methods: A randomized, open, and continuous administration design was used in trial 1 (yimitasvir phosphate capsules with sofosbuvir tablets). 28 subjects were randomly divided into two groups. A non-randomized, open design was used in trial 2 (yimitasvir phosphate capsules with omeprazole magnesium enteric-coated tablets), and included 42 subjects divided into three groups. The open design method was used in trial 3 (yimitasvir phosphate capsules with rosuvastatin calcium tablets), and included 14 subjects. The plasma concentrations of yimitasvir phosphate, sofosbuvir and their main metabolites GS-331007, omeprazole and rosuvastatin were validated by a liquid chromatography/tandem mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated by Phoenix winNonlin software. Results: (1) in trial 1, after single and co-administration, the 90% CI of sofosbuvir C(max) and AUC(0-tau) geometric mean ratio (GMR) were 152.0% (118.0% ~ 197.0%) and 230.0% (184.0% ~ 287.0%), with an increase of 52.0% and 130.0% compared to single dose of sofosbuvir, respectively. The 90% CI of GS-331007 C(max) GMR was 74.0% (67.5% ~ 81.2%) and reduced by 26% compared to single dose of sofosbuvir. (2) in trial 2, the 90% CI of C(max) GMR after yimitasvir single or co-administration at the same time, with a 4-hours interval, or with a 12- hours interval were 68.9% (44.5% ~ 106.7%) , 64.0% (43.8% ~ 93.6%) and 56.4%(38.9% ~ 81.9%), and the 90% CI of AUC(0-t) GMR were 68.6% (46.5% ~ 101.2%), 68.3% (47.6% ~ 98.0%) and 60.5% (41.8% ~ 87.5%), respectively. Compared with single dose of yimitasvir, the C(max) and AUC(0-t) were decreased by 31.1% and 31.4%, 36.0% and 31.7%, 43.6% and 39.5%, respectively. (3) In trial 3, after single and co-administration, the 90% CI of rosuvastatin C(max) and AUC(0-72) GMR were 172.4% (153.6% ~ 193.5%) and 158.0% (144.3% ~ 172.9%), respectively, with an increase of 74.9% and 60.5% compared to single dose of rosuvastatin. There were no serious adverse events and adverse events leading to withdrawal from the trial. Conclusion: Yimitasvir phosphate capsules have drug-drug interactions with sofosbuvir tablets, omeprazole magnesium enteric-coated tablets, and rosuvastatin calcium tablets.

[Clinical value of extended radical resection for pT3 stage gallbladder cancer]

Objective: To investigate the clinical value of extended radical resection for stage pT3 gallbladder cancer (GBC). Methods: The clinical and pathological data of 323 patients with stage pT3 GBC who received regional radical resection or extended radical resection in 7 domestic hepatobiliary centers in China from January 2013 to December 2018 were retrospectively analyzed. The propensity score matching method was used to select 36 cases in each of the regional radical resection group (group A1) and the extended radical resection group (group B1). The surgical indicators and overall survival rates of the two groups were compared, and prognostic factors were analyzed. Results: The number of positive lymph nodes [2(0,3)] and the total number of lymph nodes removed [3(1,4)] in group B1 were both higher than those in group A1 [1(0,1), 4(2,7)] (all P<0.05). There was no significant difference in other clinical and pathological factors between the two groups (all P>0.05). The 1, 3, and 5-year survival rates of group A1 were 75%, 44%, and 29%, respectively, which were significantly higher than those of group B1 of 50%, 15%, and 11% (χ(2)=11.311, all P<0.001). Extensive radical resection (HR=2.161, 95%CI: 1.222-3.821), hepatic parenchymal invasion (HR=2.324, 95%CI: 1.305-4.139), positive lymph node rate ≥1/3 (HR=2.927, 95%CI: 1.641-5.220), and ⅢB/ⅣB staging (HR=3.325, 95%CI: 1.750-6.320) are risk factors for the prognosis of GBC patients (all P<0.05), of which extended radical resection (HR=1.969, 95%CI: 1.083-3.581) was an independent risk factor for prognosis (P<0.05). When the ratio of positive lymph nodes was<1/3 and the tumor invaded the hepatic parenchyma, the overall survival rate of group B1 was significantly lower than that of group A1 (all P<0.05). Conclusions: The overall survival rate in patients with stage pT3 GBC whose lymph node positive rate<1/3 and/or hepatic parenchymal invaded cannot be improved by extended radical resection. Extended radical resection is an independent risk factor for patient prognosis.

A Mechanosensory Receptor TMC Regulates Ovary Development in the Brown Planthopper Nilaparvata lugens

Transmembrane channel-like (TMC) genes encode a family of evolutionarily conserved membrane proteins. Mutations in the TMC1 and TMC2 cause deafness in humans and mice. However, their functions in insects are is still not well known. Here we cloned three tmc genes, Nltmc3, Nltmc5, and Nltmc7 from brown planthoppers. The predicted amino acid sequences showed high identity with other species homologs and have the characteristic eight or nine transmembrane domains and TMC domain architecture. We detected these three genes in all developmental stages and examined tissues. Interestingly, we found Nltmc3 was highly expressed in the female reproductive organ especially in the oviduct. RNAi-mediated silencing of Nltmc3 substantially decreased the egg-laying number and impaired ovary development. Our results indicate that Nltmc3 has an essential role in the ovary development of brown planthoppers.

[Preparation and preliminary research on the characteristics of modified nano-bioglass hydrogel]

Objective: To explore the preparation and preliminary research on the characteristics of modified nano-bioglass hydrogel. Methods: (1) The nano-bioglass suspension was prepared by adding 67 mL nano-silica suspension into 400 mL saturated calcium hydroxide solution, and its suspension stability was observed. (2) The hydrogel with final mass fraction of 10% gelatin and 1% sodium alginate was prepared and set as control group. On the basis of the hydrogel in control group, the nano-bioglass suspension prepared in experiment (1) was added to prepare the hydrogel with the final mass fraction of 0.5% bioglass, 10% gelatin, and 1% sodium alginate, and the hydrogel was set as the experimental group. The gelling time at 4 and 25 ℃and the dissolution time at 37 ℃ of hydrogel in 2 groups were recorded, and the gelation at 4 and 25 ℃and dissolution condition at 37 ℃of the hydrogel in 2 groups were observed. The hydrogel in 2 groups were collected and cross-linked with 25 g/L calcium chloride solution after cold bath at 4 ℃, and the compression modulus was measured by Young's modulus tester. In addition, the hydrogel in 2 groups were collected and cross-linked as before, and freeze-drying hydrogel was made at -20 ℃. The relative volumes were measured and the porosity of hydrogel in 2 groups was calculated. The number of sample in the experiment was 3. (3) Fibroblasts (Fbs) were isolated and cultured from 12 C57BL/6J mice of 24 hours old and the morphology was observed by inverted microscope, and the third passage of Fbs were cultured for the following experiment. Fbs were collected to make single cell suspension with the cell concentration of 1×10(5)/mL. The single cell suspension was divided into experimental group and control group according the random number table (the same grouping method below), which were added with hydrogel in experimental group and control group prepared in experiment (2), respectively. At culture hour 12, 24, and 48, cells of 3 wells in each group were collected to detect the survival rate by cell counting kit 8 method. (4) The third passage Fbs were collected to prepare the single cell suspension with the cell concentration of (3.0~4.5)×10(7)/mL, which was divided into experimental group and control group, with 1 tube in each group. The single cell suspension in 2 groups were added with green fluorescent probe DIO for staining and then added with 9 mL hydrogel in experimental group and control group prepared in experiment (2), respectively. The mixed solution of Fbs and hydrogel in 2 groups was cross-linked as before to make cell-loaded hydrogel. On culture day 3, the survival of cells in the hydrogel was observed by laser confocal microscope. The cell-loaded hydrogel was prepared as before and without added with green fluorescent probe DIO. On culture day 7, the adhesion and extension of cells in the hydrogel were observed by scanning electron microscope. (5) Twelve 6-week-old female BALB/c-nu nude mice were collected and divided into experimental group and control group, with 6 mice in each group. A round full-thickness skin defect wound with diameter of 1 cm was made on the back of each mouse. Immediately after injury, one cell-loaded hydrogel block in the experimental group and the control group prepared in experiment (4) was placed in the wound of each mouse in the experimental group and the control group, respectively. On post injury day (PID) 7 and 14, 3 nude mice in each group were sacrificed to collect the wound and wound margin tissue, which was stained with hematoxylin-eosin to observe the wound healing. Data were statistically analyzed with independent sample t test. Results: (1) The nano-bioglass particles could be uniformly dispersed in water and had good suspension stability. (2) The hydrogels of the 2 groups were molten at 37 ℃, and no precipitation of particle was observed. The dissolving time of the hydrogel in the experimental group and the control group at 37 ℃ was 5 and 10 min, respectively. The gelation time of the hydrogel in the experimental group and the control group at 25 ℃ was 30 and 180 min, respectively, and the gelation time of the 2 groups at 4 ℃ was 5 and 10 min, respectively. The compression modulus of hydrogel in the experimental group was (53±6) kPa, which was significantly higher than (23±6) kPa in the control group (t=6.364, P<0.01). The porosity of the hydrogel in the experimental group was (86.1±2.1)%, which was similar to (88.2±4.4)% in the control group (t=1.210, P>0.05). (3) The cells were in long fusiform, and the proportion of nuclei was high, which was accorded with the morphological characteristics of Fbs. At culture hour 12, 24, and 48, the survival rate of cells in the experimental group was (84±4)%, (89±4)%, and (130±10)%, which was similar to (89±5)%, (90±4)%, and (130±11)% in the control group, respectively (t=1. 534, 0.611, 0.148, P>0.05). (4) On culture day 3, the cells in the two groups had complete morphology in the hydrogel, no nuclear lysis or disappearance were observed, the cytoplasm remained intact, and the fluorescence intensity of the cells in the experimental group was significantly stronger than that in the control group. On culture day 7, the cells in the experimental group and the control group adhered and stretched in the hydrogel, and the number of cells in the experimental group adhered to the hydrogel was significantly more than that in the control group. On PID 7, the wound area of the nude mice in the control group and the experimental group were reduced, the reduction area of mice in the experimental group was more obvious, and a large amount of inflammatory cells were seen in and around the wound in the 2 groups. On PID 14, the wound area of the nude mice in the control group was larger than that of the experimental group, and the number of inflammatory cells in and around the wound was significantly more than that in the experimental group. Conclusions: Nano-bioglass hydrogel possesses good physical, chemical, and biological properties, cell loading potential, and the ability to promote wound healing, which means it has a good potential in clinical application.