Linxian County in Henan Province, Northern China is known as the region with the highest incidence and mortality rate of esophageal cancer worldwide. Since 1959, the Henan medical team has conducted field work on esophageal cancer prevention and treatment in Linxian. Through three generations of effort exerted by oncologists over 65 years of research on esophageal cancer prevention and treatment in Linxian, the incidence rate of esophageal squamous cell carcinoma in this area has dropped by nearly 50%, and the 5-year survival rate has increased to 40%, reaching the international leading level. This article aims to summarize the history, present opportunities and new challenges, and explore the experience of esophageal cancer prevention and treatment in Linxian (referred to as the “Linxian experience”), providing reference and guidance to cancer prevention and treatment research in China.

This study aims to investigate the effect of salvianolic acid B (Sal B), the active ingredient of Salvia miltiorrhiza, on H9C2 cardiomyocytes injured by oxygen and glucose deprivation/reperfusion (OGD/R) through regulating mitochondrial fission and fusion. The process of myocardial ischemia-reperfusion injury was simulated by establishing OGD/R model. The cell proliferation and cytotoxicity detection kit (cell counting kit-8, CCK-8) was used to detect cell viability; the kit method was used to detect intracellular reactive oxygen species (ROS), total glutathione (t-GSH), nitric oxide (NO) content, protein expression levels of mitochondrial fission and fusion, apoptosis-related detection by Western blot. Mitochondrial permeability transition pore (MPTP) detection kit and Hoechst 33342 fluorescence was used to observe the opening level of MPTP, and molecular docking technology was used to determine the molecular target of Sal B. The results showed that relative to control group, OGD/R injury reduced cell viability, increased the content of ROS, decreased the content of t-GSH and NO. Furthermore, OGD/R injury increased the protein expression levels of dynamin-related protein 1 (Drp1), mitofusions 2 (Mfn2), Bcl-2 associated X protein (Bax) and cysteinyl aspartate specific proteinase 3 (caspase 3), and decreased the protein expression levels of Mfn1, increased MPTP opening level. Compared with the OGD/R group, it was observed that Sal B had a protective effect at concentrations ranging from 6.25 to 100 μmol·L^-1. Sal B decreased the content of ROS, increased the content of t-GSH and NO, and Western blot showed that Sal B decreased the protein expression levels of Drp1, Mfn2, Bax and caspase 3, increased the protein expression level of Mfn1, and decreased the opening level of MPTP. In summary, Sal B may inhibit the opening of MPTP, reduce cell apoptosis and reduce OGD/R damage in H9C2 cells by regulating the balance of oxidation and anti-oxidation, mitochondrial fission and fusion, thereby providing a scientific basis for the use of Sal B in the treatment of myocardial ischemia reperfusion injury.

The molecularly imprinted polymers membranes(MIPMs)were prepared for selective adsorption of lamotrigine(LTG)in plasma by surface molecular imprinting technology with polyvinylidenefluoride(PVDF)membranes as supporter,lamotrigine as template molecule,methyl methacrylate as functional monomer,ethylene glycol dimethacrylate as cross-linking agent,azodiisobutyronitrile as initiator and acetonitrile-dimethylformamide(1∶1.5,V/V)as pore-forming agent.The prepared MIPMs were characterized by scanning electron microscope,Fourier transform infrared spectroscopy,Brunaner-emmet-teller measurements,X-ray photoelectron spectroscopy,and thermogravimetric analysis.The adsorption properties of the materials were investigated by kinetic adsorption,isothermal adsorption,selective adsorption,adsorption-desorption and reusability experiments.The results showed that the imprinted layer of LTG was successfully coated on the surface of PVDF,and the materials had uniform particle size.The adsorption capacity and imprinting factor of the MIPMs towards LTG were 3.77 mg/g and 8.97,respectively.The nanomaterials showed fast mass transfer rate(30 min)and good reusability(the adsorption efficiency was 86.66%after 6 cycles),and could be used for the adsorption of LTG in plasma with low matrix interference,recoveries of 86.54%-90.48%and RSD of 1.51%-3.15%(n=5).The proposed LTG MIPMs were demonstrated to be simple and environment friendly,and had high selectivity in rapid separation and extraction of LTG in plasma.

ObjectiveTo explore whether the mechanism of Shuangshen Ningxin capsules （SSNX） in alleviating myocardial ischemia-reperfusion injury （MIRI） in rats is related to the regulation of mitochondrial fission and fusion. MethodThis study focused on Sprague Dawley （SD） rats and ligated the left anterior descending branch of the coronary artery to construct a rat model of MIRI. The rats were divided into the sham operation group， model group， SSNX group （90 mg·kg^-1） and trimetazidine group （5.4 mg·kg^-1）. The activity of superoxide dismutase （SOD） and the content of malondialdehyde （MDA） were detected by micro method. Changes in mitochondrial membrane potential （△Ψm） and the degree of mitochondrial permeability transition pore （mPTP） opening were detected by the chemical fluorescence method. The intracellular adenosine triphosphate （ATP） level was detected by the luciferase assay. The messenger ribonucleic acid （mRNA） and protein expression levels of mitochondrial fission and fusion related factors dynamin-related protein 1 （DRP1）， mitochondrial fission 1 protein （FIS1）， optic atrophy protein 1 （OPA1）， mitochondrial outer membrane fusion protein 1 （MFN1）， and MFN2 were detected by real-time polymerase chain reaction （real-time PCR） and Western blot. ResultCompared with the sham operation group， the model group showed a decrease in serum SOD activity and an increase in MDA content. The opening level of mPTP， the level of △Ψm and ATP content decreased， the protein expressions of mitochondrial fission factors DRP1 and FIS1 increased， and the protein expressions and mRNA transcription levels of fusion related factors OPA1 and MFN1 decreased. Compared with the model group，SSNX significantly increased serum SOD activity， reduced MDA content， increased intracellular ATP level and △Ψm， reduced the opening level of mPTP， downregulated the protein expressions of mitochondrial fission factors DRP1 and FIS1， and increased the mRNA transcription levels and protein expressions of fusion related factors OPA1 and MFN1. ConclusionSSNX inhibits the expressions of mitochondrial fission factors DRP1 and FIS1， and increases the expressions of fusion related factors OPA1 and MFN1， inhibiting mitochondrial fission and increasing mitochondrial fusion， thereby alleviating MIRI.

Objective:To analysis the job preference and heterogeneity of medical students by distinguishing their birthplaces,and to provide reference for optimizing the management of primary health care resources.Methods:Using a cluster sampling method,an online survey of discrete choice experiment was conducted with 925 medical students from six teaching hospitals in Beijing,741 valid questionnaires were obtained,the effective recovery rate was 80.1%.The mixed logit model was used to perform regression analysis on six job attributes and estimate the willingness to pay.Results:There were significant differences in the choice of work location among medical students from different birthplaces.The subgroup results showed that compared to medical students from city,undergraduates from rural and county district preferred a work with sufficient career development opportunities.The results of undergraduate subgroup showed that undergraduates from rural district preferred a work with good environment than those from other birthplaces.Conclusion:There is heterogeneity in job preferences of medical students from different birthplaces.Policy makers should pay attention to the medical students'birthplace,also take the educational level into account to optimize the diversified job attributes,formulating targeted intervention to attract primary health care talents.

OBJECTIVES: To analyze the gross pathological data of sudden cardiac death (SCD) with different causes, to provide data support for the identification of sudden cardiac death with unknown causes. METHODS: A total of 167 adult SCD cases in the archive of the Forensic Expertise Institute of Nanjing Medical University from 2010 to 2020 were collected. The gross pathological data of SCD cases were summarized and the characteristics of different causes of death were statistically analyzed. RESULTS: The ratio of male to female SCD cases was 3.4∶1. Coronary heart disease was the leading cause of SCD, and mainly distributed in people over 40 years old. SCD caused by myocarditis was mainly distributed in young people and the mean age of death was (34.00±9.55) years. By analyzing the differences in cardiac pathological parameters of SCD with different causes, it was found that the aortic valve circumference was significantly dilated in the SCD caused by aortic aneurysm or dissection (P<0.05). The heart weight of SCD caused by aortic aneurysm or dissection and combined factors was greater, and both pulmonary and tricuspid valvular rings were dilated in the SCD caused by combined factors in adult males (P<0.05). CONCLUSIONS Various gross pathological measures of SCD with different causes are different, which has reference value in the cause of death identification of SCD.
Humans ; Adult ; Male ; Female ; Adolescent ; Young Adult ; Death, Sudden, Cardiac/pathology* ; Coronary Disease ; Heart ; Forensic Medicine ; Autopsy

The efficacy of HPV vaccine in preventing cervical cancer has been demonstrated in numerous clinical trials and clinical uses. The follow-up after clinical trials usually last for 5-6 years to evaluate the long-term efficacy, and a series of long-term follow-up studies have been conducted in some regions. The literature retrieval of HPV vaccine long term efficiency research both at home and abroad indicated that the protective efficacy of the vaccine against vaccine-type-related cervical intraepithelial neoplasia grade 2 and above is higher than 90%.
Humans ; Human Papillomavirus Viruses ; Biomedical Research ; Papillomavirus Vaccines

OBJECTIVE: To summarize the surgical treatment of different proximal clavicle fractures, and discuss the classification of proximal clavicle fractures. METHODS: Total of 24 patients with displaced proximal clavicle fractures were treated from January 2017 to December 2020 including 16 males and 8 females, aged 28 to 66 years old. Among them, 20 cases were fresh fractures and 4 cases were old fractures. According to the Edinburgh classification, 14 cases were type 1B1 fractures and 10 cases were type 1B2 fractures. The different internal fixation methods were selected for internal fixation treatment according to different fracture types.The operation time, blood loss, preoperative and postoperative displacement difference, fracture healing time and Rockwood scoring system were recorded. RESULTS: All patients were followed up for 12 to 24 months. There were no patients with infection or loss of reduction after the operation. Three patients had internal fixation failure after operation, and the internal fixation device was removed. Results The operation time was 30 to 65 min, and the blood loss was 15 to 40 ml. No important nerves, blood vessels, or organs were damaged. The imaging healing time was 3 to 6 months. According to the Rockwood functional score, the total score was (13.50±1.86), pain (2.57±0.50), range of motion (2.78±0.41), muscle strength (2.93±0.28), restricted daily activity (2.85±0.35), subjective results (2.63±0.61);the results were excellent in 20 cases, good in 3 cases, fair in 1 case. CONCLUSION Proximal clavicular fracture is a type of fracture with low incidence. According to different fracture types, different internal fixation methods and treatment methods can be selected, and satisfactory surgical results can be achieved.
Male ; Female ; Humans ; Adult ; Middle Aged ; Aged ; Clavicle/surgery* ; Treatment Outcome ; Bone Plates ; Fractures, Bone/surgery* ; Fracture Fixation, Internal/methods* ; Retrospective Studies

OBJECTIVE: With the help of finite element analysis, to explore the effect of proximal humeral bone cement enhanced screw plate fixation on the stability of internal fixation of osteoporotic proximal humeral fracture. METHODS: The digital model of unstable proximal humeral fracture with metaphyseal bone defect was made, and the finite element models of proximal humeral fracture bone cement enhanced screw plate fixation and common screw plate fixation were established respectively. The stress of cancellous bone around the screw, the overall stiffness, the maximum stress of the plate and the maximum stress of the screw were analyzed. RESULTS: The maximum stresses of cancellous bone around 6 screws at the head of proximal humeral with bone cement enhanced screw plate fixation were 1.07 MPa for No.1 nail, 0.43 MPa for No.2 nail, 1.16 MPa for No.3 nail, 0.34 MPa for No.4 nail, 1.99 MPa for No.5 nail and 1.57 MPa for No.6 nail. These with common screw plate fixation were:2.68 MPa for No.1 nail, 0.67 MPa for No.2 nail, 4.37 MPa for No.3 nail, 0.75 MPa for No.4 nail, 3.30 MPa for No.5 nail and 2.47 MPa for No.6 nail. Overall stiffness of the two models is 448 N/mm for bone cement structure and 434 N/mm for common structure. The maximum stress of plate appears in the joint hole:701MPa for bone cement structure and 42 0MPa for common structure. The maximum stress of screws appeared at the tail end of No.4 nail:284 MPa for bone cement structure and 240.8 MPa for common structure. CONCLUSION Through finite element analysis, it is proved that the proximal humerus bone cement enhanced screw plate fixation of osteoporotic proximal humeral fracture can effectively reduce the stress of cancellous bone around the screw and enhance the initial stability after fracture operation, thus preventing from penetrating out and humeral head collapsing.
Humans ; Finite Element Analysis ; Bone Cements ; Polymethyl Methacrylate ; Biomechanical Phenomena ; Shoulder Fractures/surgery* ; Fracture Fixation, Internal ; Humeral Head ; Bone Screws ; Bone Plates

Objective: To explore the effects of three-dimensional (3D) bioprinting gelatin methacrylamide (GelMA) hydrogel loaded with nano silver on full-thickness skin defect wounds in rats. Methods: The experimental research method was adopted. The morphology, particle diameter, and distribution of silver nanoparticles in nano silver solution with different mass concentrations and the pore structure of silver-containing GelMA hydrogel with different final mass fractions of GelMA were observed by scanning electron microscope and the pore size was calculated. On treatment day 1, 3, 7, and 14, the concentration of nano silver released from the hydrogel containing GelMA with final mass fraction of 15% and nano silver with final mass concentration of 10 mg/L was detected by mass spectrometer. At 24 h of culture, the diameters of inhibition zone of GelMA hydrogel containing final mass concentration of 0 (no nano silver), 25, 50, and 100 mg/L nano silver against Staphylococcus aureus and Escherichia coli were detected. Fibroblasts (Fbs) and adipose stem cells (ASCs) were isolated respectively by enzymatic digestion using the discarded prepuce after circumcision from a 5-year-old healthy boy who was treated in the Department of Urology of the Second Affiliated Hospital of Zhejiang University School of Medicine in July 2020, and the discarded fat tissue after liposuction from a 23-year-old healthy woman who was treated in the Department of Plastic Surgery of the Hospital in July 2020. The Fbs were divided into blank control group (culture medium only), 2 mg/L nano sliver group, 5 mg/L nano sliver group, 10 mg/L nano sliver group, 25 mg/L nano sliver group, and 50 mg/L nano sliver group, which were added with the corresponding final mass concentrations of nano sliver solution, respectively. At 48 h of culture, the Fb proliferation viability was detected by cell counting kit 8 method. The Fbs were divided into 0 mg/L silver-containing GelMA hydrogel group, 10 mg/L silver-containing GelMA hydrogel group, 50 mg/L silver-containing GelMA hydrogel group, and 100 mg/L silver-containing GelMA hydrogel group and then were correspondingly treated. On culture day 1, 3, and 7, the Fb proliferation viability was detected as before. The ASCs were mixed into GelMA hydrogel and divided into 3D bioprinting group and non-printing group. On culture day 1, 3, and 7, the ASC proliferation viability was detected as before and cell growth was observed by live/dead cell fluorescence staining. The sample numbers in the above experiments were all 3. Four full-thickness skin defect wounds were produced on the back of 18 male Sprague-Dawley rats aged 4 to 6 weeks. The wounds were divided into hydrogel alone group, hydrogel/nano sliver group, hydrogel scaffold/nano sliver group, and hydrogel scaffold/nano sliver/ASC group, and transplanted with the corresponding scaffolds, respectively. On post injury day (PID) 4, 7, 14, and 21, the wound healing was observed and the wound healing rate was calculated (n=6). On PID 7 and 14, histopathological changes of wounds were observed by hematoxylin eosin staining (n=6). On PID 21, collagen deposition of wounds was observed by Masson staining (n=3). Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, Bonferroni correction, and independent sample t test. Results: The sliver nano particles in nano silver solution with different mass concentrations were all round, in scattered distribution and uniform in size. The silver-containing GelMA hydrogels with different final mass fractions of GelMA all showed pore structures of different sizes and interconnections. The pore size of silver-containing GelMA hydrogel with 10% final mass fraction was significantly larger than that of silver-containing GelMA hydrogels with 15% and 20% final mass fractions (with P values both below 0.05). On treatment day 1, 3, and 7, the concentration of nano silver released from silver-containing GelMA hydrogel in vitro showed a relatively flat trend. On treatment day 14, the concentration of released nano silver in vitro increased rapidly. At 24 h of culture, the diameters of inhibition zone of GelMA hydrogel containing 0, 25, 50, and 100 mg/L nano silver against Staphylococcus aureus and Escherichia coli were 0, 0, 0.7, and 2.1 mm and 0, 1.4, 3.2, and 3.3 mm, respectively. At 48 h of culture, the proliferation activity of Fbs in 2 mg/L nano silver group and 5 mg/L nano silver group was both significantly higher than that in blank control group (P<0.05), and the proliferation activity of Fbs in 10 mg/L nano silver group, 25 mg/L nano silver group, and 50 mg/L nano silver group was all significantly lower than that in blank control group (P<0.05). Compared with the that of Fbs in 0 mg/L silver-containing GelMA hydrogel group, the proliferation activity of Fbs in 50 mg/L silver-containing GelMA hydrogel group and 100 mg/L silver-containing GelMA hydrogel group was all significantly decreased on culture day 1 (P<0.05); the proliferation activity of Fbs in 50 mg/L silver-containing GelMA hydrogel group was significantly increased (P<0.05), while the proliferation activity of Fbs in 100 mg/L silver-containing GelMA hydrogel group was significantly decreased on culture day 3 (P<0.05); the proliferation activity of Fbs in 100 mg/L silver-containing GelMA hydrogel group was significantly decreased on culture day 7 (P<0.05). The proliferation activity of ASCs in 3D bioprinting group show no statistically significant differences to that in non-printing group on culture day 1 (P>0.05). The proliferation activity of ASCs in 3D bioprinting group was significantly higher than that in non-printing group on culture day 3 and 7 (with t values of 21.50 and 12.95, respectively, P<0.05). On culture day 1, the number of dead ASCs in 3D bioprinting group was slightly more than that in non-printing group. On culture day 3 and 5, the majority of ASCs in 3D bioprinting group and non-printing group were living cells. On PID 4, the wounds of rats in hydrogel alone group and hydrogel/nano sliver group had more exudation, and the wounds of rats in hydrogel scaffold/nano sliver group and hydrogel scaffold/nano sliver/ASC group were dry without obvious signs of infection. On PID 7, there was still a small amount of exudation on the wounds of rats in hydrogel alone group and hydrogel/nano sliver group, while the wounds of rats in hydrogel scaffold/nano sliver group and hydrogel scaffold/nano sliver/ASC group were dry and scabbed. On PID 14, the hydrogels on the wound surface of rats in the four groups all fell off. On PID 21, a small area of wounds remained unhealed in hydrogel alone group. On PID 4 and 7, the wound healing rates of rats in hydrogel scaffold/nano sliver/ASC group were significantly higher than those of the other three groups (P<0.05). On PID 14, the wound healing rate of rats in hydrogel scaffold/nano sliver/ASC group was significantly higher than the wound healing rates in hydrogel alone group and hydrogel/nano sliver group (all P<0.05). On PID 21, the wound healing rate of rats in hydrogel alone group was significantly lower than that in hydrogel scaffold/nano sliver/ASC group (P<0.05). On PID 7, the hydrogels on the wound surface of rats in the four groups remained in place; on PID 14, the hydrogel in hydrogel alone group was separated from the wounds of rats, while some hydrogels still existed in the new tissue of the wounds of rats in the other three groups. On PID 21, the collagen arrangement in the wounds of rats in hydrogel alone group was out of order, while the collagen arrangement in the wounds of rats in hydrogel/nano sliver group, and hydrogel scaffold/nano sliver/ASC group was relatively orderly. Conclusions: Silver-containing GelMA hydrogel has good biocompatibility and antibacterial properties. Its three-dimensional bioprinted double-layer structure can better integrate with new formed tissue in the full-thickness skin defect wounds in rats and promote wound healing.
Male ; Rats ; Animals ; Humans ; Hydrogels/pharmacology* ; Bioprinting ; Metal Nanoparticles ; Rats, Sprague-Dawley ; Silver/pharmacology* ; Soft Tissue Injuries ; Anti-Bacterial Agents