Objective To analyze the detection situation and variation tendency of volatile components of organic solvents in enterprises in Longgang District, Shenzhen City. Methods A total of 368 enterprises using organic solvents in Longgang District, Shenzhen City from 2019 to 2022 were selected as the research subjects using judgment sampling method. And its 2 086 reports of occupational hazards monitoring on volatile components of organic solvents in workplaces from 2019 to 2022 were collected for analysis. Results Among the 2 086 organic solvent samples, the top 10 chemical substances in terms of detection rates were toluene, methanol, xylene, n-hexane, ethylbenzene, dimethoxymethane, dichloromethane, acetone, ethyl acetate and cyclohexane, with detection rates ranging from 16.73% to 29.72%. The detection rate of benzene in organic solvent samples from 368 enterprises decreased from 13.84% to 5.13% from 2019 to 2022 (P<0.01). The detection rate of trichlorethylene decreased from 3.58% to 0.45% (P<0.01), and the detection rate of dichloroethane decreased from 4.53% to 1.81% (P<0.01). However, the reduction in the detection rate of n-hexane was not significant (from 28.88% to 23.08%, P>0.05). Benzene had relatively high detection rates in yellow glue, super glue, and thinner (10.94%, 10.00%, and 8.45%, respectively). The detection rate of n-hexane was relatively high in super glue, cleaning agent and car wash liquids (90.00%, 61.84%, and 46.81%, respectively). The detection rate of trichlorethylene was relatively high in cleaning agent (3.95%), and the detection rate of dichloroethane was relatively high in super glue (40.00%). Conclusion From 2019 to 2022, the detection rates of traditional occupational hazards such as benzene, trichloroethylene, and dichloroethane in the volatile organic components used in Longgang District enterprises showed a downward trend.

BACKGROUND:Avascular necrosis of the femoral head is a refractory orthopedic disease that seriously affects the normal life of patients.Hip preservation is recommended for young patients due to the limited prosthesis longevity and revision.Accurate prediction of the mechanical properties of the necrotic area in the early stage and then intervention is the key to hip preservation. OBJECTIVE:To establish a dynamic contact mechanics finite element model of necrotic femoral head based on human hip CT data and predict effects of both necrotic volume magnitude and its position on biomechanics of the necrotic region under walking movement. METHODS:CT data of a volunteer were collected and then geometry model of the hip was rebuilt.Finite element model of the necrotic femoral head was established using the Abaqus software.Nine different necrotic femoral models were constructed by combined both three different necrotic volume magnitudes(small,medium and big volume)and three different necrotic positions(coincided with,medium deviated with and kept away from the line of the force).The Von Mises of the necrotic region for all models were predicted under both 3 000 N static load and dynamical loads of one whole ISO walking gait cycle.The collapse risk for all models was evaluated based on collapse criterion. RESULTS AND CONCLUSION:(1)More approaching of the necrotic region to the line of force and bigger collapse volume made the maximum Von Mises increasing.This also enlarged the collapse risk of the necrotic region.(2)For different load types,walking movement increased the maximum Von Mises of the necrotic region than that of the value under static load under the same necrotic volume and location.(3)In conclusion,dynamic load would result in increasing of the maximum Von Mises of the necrotic region comparing to static load during exercise.Therefore,the risk of local collapse will increase due to greater Von Mises.However,the overall collapse risk is lower than that of static load due to the dynamic change of bearing area.This factor should be carefully considered by surgeons when they evaluate the mechanical performance of the necrotic femoral head.

Objective To explore the effect of MSCT 3D scanning and reconstruction on developmental dysplasia of the hip(DDH)in adult patients with total hip arthroplasty,The predictive value of acetabular prosthesis selection and osteotomy accuracy in THA.Methods Selection in our hospital between February 2021 and February 2023 were 60 adult DDH patients underwent total hip replacement,which USES routine preoperative planning as a control group of 30 patients,and using MSCT + reconstruction of 3 d scanning technology as observation group of 30 patients,planning after the completion of the planning of the surgical operation and implant placement,Relevant information was collected before and after the operation of the two groups.Operation time,intraoperative blood loss,intraoperative fluoroscopy time,acetabular prosthesis selection and matching rate,femur split fracture rate,pelvis and acetabular reduction quality,Majeed score and Harris hip function score were compared between the two groups.The osteotomy distance and sharp shoulder distance of the two groups were compared before planning and in actual conditions,and the correlation between MSCT 3D scanning and reconstruction technology and the accuracy of acetabular prosthesis selection was evaluated.Results Results analysis showed that MSCT 3D scanning+reconstruc-tion technology used in preoperative evaluation of patients in the observation group was correlated with the accuracy of acetabular prosthesis selection(P＜0.05),and the absolute errors of osteotomy distance and sharp shoulder distance of patients in the observation group were smaller than the actual situation before planning(P＜0.05).In addition,compared with the control group,the operative time,intraoperative blood loss,intraoperative fluoroscopy time and incidence of femoral split fracture in the observation group were significantly lower,and the matching rate of acetabular prosthesis selection,the Majeed scores and Harris scores were significantly higher in the following 3 months were significantly higher(P＜0.05).The reduction quality of pelvis and acetabulum was not statistically significant between the two groups(P＞0.05).Conclusion Msct-based 3D scanning + reconstruction has a high predictive value for the selection of acetabular prosthesis and the accuracy of osteotomy in adult DDH total hip replacement,and the use of this technology for preoperative planning has a significant optimization effect on the actual treatment effect and patient recovery.

Objective:To evaluate the effect of strict intraoperative blood glucose control on postoperative hepatic allograft dysfunction in patients undergoing liver transplantation.Methods:A total of 164 patients of both sexes, aged 18-64 yr, with body mass index of 18-30 kg/m 2, of American Society of Anesthesiologists Physical Status classification Ⅲ or Ⅳ, undergoing orthotopic liver transplantation, were divided into strict intraoperative blood glucose control group (group S, 6.0-7.8 mmol/L) and routine blood glucose control group (group C, 4.1-10.0 mmol/L) using a random number table method. From the completion of anesthesia induction to the end of operation, arterial blood glucose was measured every 1 h, and blood glucose management was carried out in combination with the goal-oriented blood glucose control process. The occurrence of postoperative hepatic allograft dysfunction, infection within 30 days after surgery, offline extubation time, duration of intensive care unit stay and total length of hospital stay were recorded. Results:Compared with group C, the incidence of postoperative liver dysfunction and infection within 30 days after operation were significantly decreased ( P<0.05), and no significant change was found in the offline extubation time, duration of intensive care unit stay and total length of hospital stay in group S ( P>0.05). Conclusions:Strict blood glucose control during liver transplantation can decrease the development of postoperative liver dysfunction in patients.

Objective To investigate the difference of matrix stiffness in different regions of tibial plateau in osteoarthritis (OA) and its effects on morphology of the cartilage and mitochondria. Methods The tibial plateau cartilage specimens of OA were obtained for nanoindentation test, transmission electron microscopy and histological analysis. The stiffness of cartilage matrix in different regions of OA tibial plateau was detected by nano-indentation. The morphology of cartilage mitochondria in different regions was observed by transmission electron microscopy, and the changes of mitochondrial plane area, shape and ridge volume density were quantitatively analyzed. Cartilage injury in different regions of OA tibial plateau was observed by histological staining. Results The cartilage of OA tibial plateau showed regional heterogeneity, and the cartilage and mitochondria on medial side of varus knee OA were more severe, and the matrix stiffness was higher. The OA scores were positively correlated with matrix stiffness. There was also a significant correlation between OA scores and mitochondrial morphology: the higher OA scores, the larger and rounder mitochondrial plane area, and the lower cristae volume density. Conclusions The differences of tibial plateau revealed the correlation between cartilage matrix stiffness, OA scores and mitochondrial morphological parameters. The increased cartilage matrix stiffness may be the main cause of chondrocyte mitochondrial injury, and further aggravate the progression of OA.

【Objective】 To investigate the resource allocation status of blood testing laboratories in 14 blood stations in Gansu Province, explore the impact of differences in basic conditions on the comprehensive testing ability of laboratories, so as to promote the homogenization and standardization of blood screening capacity in blood stations in Gansu and improve blood safety and effectivenes. 【Methods】 An evaluation index system of laboratory resource allocation was constructed and a question-naire was designed. The data of human resources, infrastructure and key equipment of 14 blood stations were collected. The entropy weight -TOPSIS method was used to evaluate and rank the resource allocation of 14 blood stations. 【Results】 In the comprehensive evaluation of blood testing laboratory resource allocation in 14 blood stations in Gansu, the top three were laboratories A, B and I, and the last three were laboratories G, M and J. On the whole, the main issue was unreasonable structure of human resources: most laboratories had unreasonable age structure; except for Laboratory A, there was no personnel with bachelor's degree or above in laboratories; most laboratories had not established a team with intermediate professional titles. In terms of infrastructure, the size of seven laboratories could not meet the needs of modern laboratory testing, and all eight blood stations had no spare nucleic acid laboratories nor a mutual spare laboratory with other blood stations As for the key equipment, 5 laboratories had no automatic blood grouping diagnostic instrument, 5 laboratories only had one set of enzyme immunoassay detection system, 3 laboratories had no spare equipment for the key equipment, which means if the equipment failure could not be repaired in time, the release of results would be affected. 【Conclusion】 There were significant differences in human resources, infrastructure and key equipment of blood testing laboratories in 14 blood stations in Gansu, which had a great impact on laboratory testing capacity and subsequent development. It is suggested that governments at all levels and health administrative departments optimize the input of laboratory resource allocation according to the blood collection volume of blood stations to gradually narrow the differences in resource distribution between different regions, improve the degree of laboratory automation and optimize the personnel structure, so as to build high-quality and efficient blood testing laboratories and ensure the safety of clinical blood use.

ObjectiveTo study the clinical efficacy of Shire Biqing pill in the treatment of rheumatoid arthritis （damp-heat obstruction syndrome） and its effect on the expression of serum osteoprotegerin （OPG）， nuclear factor-κB receptor activating factor ligand （RANKL）， and tumor necrosis factor-α （TNF-α）， and to explore its mechanism from the perspective of bone destruction. MethodPatients with rheumatoid arthritis （damp-heat obstruction syndrome） were randomly divided into two groups， with 36 patients in each group. The control group was treated with methotrexate tablets and celecoxib capsule， while the treatment group was treated with Shire Biqing pill based on the control group. The treatment period was 3 months. The pain visual analogue scale （VAS） score， joint tenderness number， joint swelling number， disease activity score （DAS28-ESR）， traditional Chinese medicine （TCM） symptom quantitative score， and related adverse reactions were recorded before and after treatment， and the peripheral serum OPG， RANKL， TNF-α， erythrocyte sedimentation rate （ESR）， and Creactive protein （CRP） were detected. ResultAfter treatment， the total effective rate was 88.57% （31/35） in the treatment group and 79.41% （27/34） in the control group. The total effective rate of the treatment group was higher than that of the control group （Z=-2.089， P<0.05）. The pain VAS score， joint tenderness number， joint swelling number， and DAS28-ESR of the two groups were significantly lower than those before treatment （P<0.05）， and the pain VAS score， joint tenderness number， joint swelling number， and DAS28-ESR of the treatment group were significantly better than those of the control group after treatment （P<0.05）. Compared with that before treatment， the TCM symptom quantitative score in the two groups decreased significantly （P<0.05）， and the decrease was more obvious in the treatment group than in the control group （P<0.05）. Compared with those before treatment， the levels of RANKL， TNF-α， ESR， and CRP in the two groups decreased and the level of OPG increased （P<0.05）， and the changes in the treatment group were more obvious that in the control group （P<0.05）. There were no serious adverse events or serious adverse reactions during this clinical trial. ConclusionShire Biqing pill can effectively improve the clinical symptoms of rheumatoid arthritis （damp-heat obstruction syndrome） with good safety. Shire Biqing pill effectively regulate the OPG/RANKL/RANK system and reduce the pro-inflammatory factor TNF-α， which may be its mechanism in the intervention in rheumatoid arthritis bone destruction.

Objective:To observe the clinical characteristics of esophageal reflux after total gastrectomy (ERATG), and to explore the mechanism of occurrence.Methods:Fourteen gastric cancer patients who underwent total gastrectomy were prospectively enrolled in this study. The postoperative symptoms were observed and recorded and 24 h MII-pH with pH monitoring was performed to investigate the characteristics of postoperative reflux.Results:After total gastrectomy patients were with different degrees of ERATG as heartburn, appetite loss, chest tightness and belching. The overall nature of ERATG is mainly weak acid, with a pH between 4 and 7. ERATG involved esophageal-jejunal anastomosis and a length of esophagus 7 cm above the anastomosis. Patients with typical reflux symptoms had a lower pH minimum in the upright position than those without typical symptoms[(4.76±0.71) vs.(5.68±0.37), t=2.866, P<0.05]. Patients with typical reflux symptoms had a higher frequency of reflux of mixed liquid and liquid-air reflux than those without typical symptoms[liquid(31.25±29.76) vs.(4.50±9.14), t=0.011, P<0.05; liquid-air(19.50±12.99) vs.(2.00±2.61), t=0.004, P<0.05]. Conclusion:ERATG is mainly a upward reflux of weakly acidic gas, with typical symptoms of heartburn, appetite loss, chest tightness and belching. Patients with typical symptoms usually have lower pH in the upright position.

Objective:To understand the current status of foreign dual-degree programs of Medical Doctor (MD) and Master of Public Health (MPH) and provide evidence-based decision-making reference for promoting the education of high-level applied public health talents in China.Methods:The list of involved institutions and information of foreign MD-MPH dual-degree programs was collected through literature retrieval, online information searching, and additional survey of key figures. We extracted the details of each project regarding professional fields, core competence, length of schooling, teaching and learning arrangement, internship eligibility, and graduation assessment. Python 3.8.0 was used for data cleaning, and the occurrence frequency of related items in each dimension was calculated.Results:A total of 99 MD-MPH programs from 104 foreign institutions were included, among which 97.1% of them were implemented in universities from the United States. The School of Public Health provided 42.4% (42/99) of the programs. Epidemiology was the major discipline set up among most programs, accounting for 12.0% (29/241) of all the specialties involved. Epidemiological research methods, health policy management and practice, and public health practice were the top 3 core competencies to be mastered. Of the 99 programs, 87 gave information on the length of the program, of which 74.7% (65/87) were five years, 6.9% (6/87) were four years, and 18.4% (16/87) included both 4-year and 5-year programs.Conclusions:The international MD-MPH programs were sophisticated and mainly organized by the School of Public Health alone or in conjunction with the School of Medicine. Epidemiology is the core course and competence objective, with a length of 4-5 years. Through learning experience from international MD-MPH programs and the Chinese unique medical development background, China should optimize its medical education system to develop a suitable talent training strategy for MD-MPH dual-degree programs in the new era.

As an important platform compound, 3-hydroxypropionic acid (3-HP) can be used as a substrate to synthesize a variety of biological products with commercial potential. The titer of 3-HP by wild-type bacteria is low, which severely limits the large-scale application and production of 3-HP. By modifying the genes related to the metabolic pathway, engineered bacteria using cheap substrates as carbon sources are constructed, the aim of reducing production cost and increasing output is realized. In this paper, the recent progress in the synthesis of 3-HP by metabolic engineering at home and abroad is reviewed. The advantages and disadvantages of glycerol pathway, malonyl-CoA pathway and beta-alanine pathway for synthesis of 3-HP are also summarized and analyzed, and the future development of 3-HP is prospected.
Glycerol ; metabolism ; Industrial Microbiology ; trends ; Lactic Acid ; analogs & derivatives ; biosynthesis ; Metabolic Engineering ; Metabolic Networks and Pathways ; genetics