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In China, rural doctors (RDs) perform crucial health care missions. However, they have received less attention than their colleagues in urban public hospitals. In this specific group, a severe challenge occurs in sync with a high turnover rate and deficient job satisfaction. This study aims to systematically summarize and evaluate the influencing factors of job satisfaction and turnover intention among Chinese rural doctors. Seven databases, including PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI), were systematically retrieved, and several experts were consulted to acquire holistic publications in this domain. A total of 20 full-text papers and 22,721 samples were included. In addition, 53 influencing factors were evaluated, of which 38 factors may play a significant role. Based on Herzberg's two-factor theory, together with China's cultural tradition and national conditions, we classified these influencing factors into sociodemographic characteristic factors (n=13), incentive factors (n=18), and health care factors (n=22). Meanwhile, we discussed and analyzed the influencing factors of turnover intention and job satisfaction in detail and put forward corresponding measures and suggestions for the government. We are confident that this research provides a holistic perspective to systematically evaluate the factors influencing the job satisfaction and intention to leave of Chinese rural doctors. Importantly, we hypothesize that the illumination of cases among Chinese rural physicians applies to other countries or regions, which has significant implications for the reformation of the medical system by governments or decision-makers worldwide.

This article examines the politico-scientific mechanism, which leads nations to declare an epidemic or a pandemic finished, irrespective of the actual epidemiological situation at a given time. A historical comparison is made with the famous behavior of Emperor Justinian I (482-565 CE) during the plague pandemic named after him (part of the first plague pandemic). Finally, a reference to the importance of the multidisciplinary study of the history of medicine and the intersection between pandemics and wars is made.

Copyright © 2021 The Author(s). The pace to achieving a sustainable plastics economy remains noticeably slow due to a lack of understanding on the role and importance of stakeholder dynamics in the plastic packaging system. This study aims to unpack and assess the role of stakeholders in improving plastics recycling rates and circularity in the UK, using polyethylene terephthalate (PET) drinks bottles value chain as a case study. Via the theoretical lens of stakeholder theory we identify and group the stakeholders involved in the PET drinks bottles value chain, and integrate this in the Complex Value Optimisation for Resource Recovery (CVORR) systems thinking approach to make sense of, and analyse, stakeholders complex interactions. Results highlight that even though, external stakeholders (e.g. NGOs, trade associations) engage on different levels and scales in promoting circularity in the PET bottles value chain, there is strong drive in incentivising production and consumption processes driven by the significant lobbying power of internal stakeholders operating upstream of the PET bottles value chain (i.e. producers and brand owners). This lobbying power, which arises from the well-established market of PET bottles in the UK, and its support by financial institutions, it strongly influences national and local government policies and decision-making processes. Meanwhile, the waste management processes are short-sighted, being unable to gain improved momentum and increasing the PET bottles recycling rates. This dynamic conceals, and somewhat retains, the prevailing resistance in removing the infrastructural, regulatory and technological lock-ins. The development of an interdisciplinary collaboration between internal and external stakeholders is paramount to sustainably managing PET drinks bottles in the UK and achieving a transition to a sustainable circular plastics economy. Fostering closer collaboration between all stakeholders involved in the system, can aid the development of new value networks and support new policy interventions that can improve circularity in the plastic packaging sector. Brunel University London as part of the Brunel Research Initiative & Enterprise Fund (BRIEF) award No.11683100, in the context of ‘Closing the Plastic Food Packaging Loop’ project, and generously supported by the Oxford Martin School, University of Oxford.

This paper investigates the biochemical oxygen demand (BOD) and the pH level along Jelok River, Kajang, Selangor, Malaysia. The BOD and pH level are of major interest as microbial activity. Five water sampling locations along the river have been selected. To test the pH level of each water sample, a pH meter was used. To test the BOD of each water sample, the 5-days BOD test was conducted. Using the collected data, the Pearson’s correlation coefficient between the pH and BOD was calculated. The computed Pearson correlation coefficient is -0.67988, indicating that pH does affect BOD of the water, specifically for this river. In addition, it demonstrates that when pH value increases, BOD of the water will decrease. The results show that water pH was quite stable, range between 7.05 to 7.65, while BOD fluctuates wildly, range between 1.4 to 4.3 mg/L. According to the BOD value, the high BOD value was found along the bridge at Changkat Road with 4.3 mg/L, and the lowest was found to be the one at Shell Petrol Station along Semenyih Road with BOD value of 1.4 mg/L. From the findings, public and authority shall be alert of the water performance and actions are necessary to preserve the water quality along this river. In addition, it is recommended to compare the water quality parameters among few rivers in future studies.

Uncertainty quantification has always been an important topic in model reduction and simulation of complex systems. In this aspect, global sensitivity analysis (GSA) methods such as Fourier amplitude sensitivity test (FAST) are well recognized as effective algorithms. Recently, some data-based metamodeler such as Random Forest (RF) also developed their own variable importance selection solutions for parameters with perturbations. This paper proposes a visual comparison of these two uncertainty quantification methods, using datasets retrieved from vibroacoustic models. Their results have a lot in common and are capable to explain many results. The remarkable agreement between methods under fundamentally different definitions can potentially improve their compatibility in various occasions.

To investigate the diagnostic performance and usefulness of texture analysis in differentiating angiomyolipoma (AML) without visible fat from clear cell renal cell carcinoma (ccRCC) on four-phase contrast-enhanced computed tomography (CECT).Seventeen patients with AML without visible fat and 50 patients with ccRCC of size ≤4.5 cm who had also undergone preoperative four-phase CECT were included in this study. The histogram, grey-level co-occurrence matrix (GLCM), and grey-level run length matrix (GLRLM) were evaluated. Sequential feature selection (SFS) and support vector machine (SVM) classifier with leave-one-out cross validation were used.Using the SFS and SVM classifiers, five texture features were selected; mean (unenhanced), standard deviation (unenhanced and excretory), cluster prominence (nephrographic), and long-run high grey-level emphasis (corticomedullary). Diagnostic performance of the five selected texture features for all CT phases was as follows: 82% sensitivity, 76% specificity, 85% accuracy, and 85 area under the receiver operating characteristic curve (AUC). In the subgroup analysis, the AUCs of each phase were significantly0.5 (p0.05). In the pairwise comparison of AUCs between four phases, there were no significant differences between the four phases except the unenhanced and corticomedullary phases (p=0.015), i.e., the unenhanced phase showed slightly higher AUC than the corticomedullary phase.Texture analysis of small renal masses (≤4.5 cm) on four-phase CECT can accurately differentiate AML without visible fat from ccRCC and showed good diagnostic performance for both the unenhanced and enhanced phases.

Fast-ramping magnets will be used in the Booster Ring (BRing) of the High-Intensity Heavy Ion Accelerator Facility (HIAF), which is proposed by the Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS). The dipole magnet will provide the field quality from the injection field of 0.0496 T up to the maximum value of 1.5786 T, with the maximum ramping rate of 12 T/s. The ramping magnetic field induces eddy currents that give rise to eddy loss and large force on the beam pipe, field delay and sextupole field appear to affect the field quality provided by the BRing dipole. An in-detail understanding of these effects is an essential aspect of the design. Based on the finite-element analysis, a simplified model by use uniform background magnetic field was used to the transient simulations, eddy current and the forces on the pipe at different times on the beam pipe were performed. This paper presents the results obtained for the eddy loss and magnetic field delay for different wall thicknesses. Then, mechanical design details are presented, and also stress distribution, the deformation in the beam pipe. The analysis results revealed that the eddy current and thus the field delay and eddy current-induced Lorentz force scales linearly with the derivative of the magnetic field and the thickness of the pipe. The power losses that cause heating of the pipe is linear with the square of the derivative of the magnetic field and the thickness of the pipe.

Space Environment Simulation and Research Infrastructure (SESRI) is a new national research infrastructure under construction at Harbin Institute of Technology (HIT) in China. Its 300-MeV proton and heavy ion accelerator is a major radiation source, and a compact synchrotron has been designed with a circumference of less than 44 m. The synchrotron dipoles are essential components of the accelerator, and they have been designed and tested carefully to meet the stringent physical requirements. The measured transverse field homogeneity is less than 2 × 10-4 from 0.2 T to 1.4 T and roughly agrees with the simulated results. With a modified linear programming algorithm, the integral magnetic field uniformity within 0.2–1.1 T is optimised from 6 × 10-4 to 1.5 × 10-4, and the corresponding multi-pole field-component errors are greatly reduced. By shortening the pole ends, the reproducibility of integral field among six magnets at 0.2 T is less than 3 × 10-4. In addition, the transient effect of the magnetic field is also evaluated and tested. Through analysis of the transient effect and structural strength, low-carbon steel and stainless steel are selected for the side plates and end plates, respectively. According to the transient measurement results, the feedforward compensation can be implemented to produce a more accurate current waveform. On 1 January 2022, the beam was successfully accumulated with the preset current waveform, and the beam intensity met the design requirements.

BackgroundGlioblastoma multiforme (GBM) is a type of high-grade brain tumor known for its proliferative, invasive property, and low survival rate. Recently, with the advancement in therapeutics for tumors such as targeted therapy, individual cancer-specific biomarkers could be recognized as targets for curative purposes. This study identified six differentially expressed genes that have shown significant implications in clinical field, including FPR2, VEGFA, SERPINA1, SOX2, PBK, and ITGB3. FPR2 was of the same protein family with FPR1, and the latter has been repeatedly reported to promote motility and invasiveness of multiple tumor forms.MethodsThe gene expression profiling of 40 GBM samples and five normal samples from the TCGA database were comprehensively analyzed. The differentially expressed genes (DEGs) were identified using R package and screened by enrichment analysis and examination of protein–protein interaction networks, in order to further explore the functions of DEGs with the highest association with clinical traits and to find hub genes. A qRT-PCR and Western blots were conducted to verify the results of this study.ResultsOur investigation showed that FPR2, VEGFA, SERPINA1, SOX2, PBK, and ITGB3 were significantly up-regulated in GBM primary tumor compared to the control group. Functional enrichment analysis of the DEGs demonstrated that biological functions related to immune systems, cell division and cell cycle were significantly increased, which were closely related to tumor progression and development. Downstream construction of PPI network analysis indicated that FPR2 was a hub gene involved in high level of interaction with CR3 and VEGFA, which played a key role in inflammatory pathways and cellular dysfunction.ConclusionFPR2, VEGFA, SERPINA1, SOX2, PBK, and ITGB3 were significantly over-expressed in primary tumor samples of GBM patients and were involved in cellular functions and pathways contributing to tumor progression. Out of these six pivotal genes, we intensively focused on FPR2, and our analysis and experimental data both suggested its efficacy as a potential biomarker, serving as an alternative immunotherapeutic target for glioblastoma multiforme.

The High-Intensity Heavy Ion Accelerator Facility (HIAF), proposed by the Institute of Modern Physics, Chinese Academy of Sciences (IMP), is being designed to provide primary and radioactive intense beams for nuclear and related research. As an important part of HIAF, the Booster Ring (BRing) is a fast ramping synchrotron and is used to obtain high intensity (238U35+, 1 × 1011 ppp) and high energy (0.835 GeV/u) heavy-ion beam. Moreover, the beam rigidity of the Booster Ring varies widely from 1 Tm to 34 Tm. These require the dipole of Booster Ring to have a large-good field region, a high magnetic field homogeneity, and a wide range of magnetic field variation from 0.047 T to 1.58 T. Aiming at the properties of the dipole magnet, we adopt some new methods to improve magnetic field precision and optimize efficiency. Double symmetrical air holes in the magnet pole are used to guarantee the magnetic field homogeneity under a wide magnetic field range. At the same time, the linear programming algorithm is adopted to optimize the integral magnetic field uniformity of the iron-dominated dipole magnet, which improves the integral magnetic field precision and optimization efficiency. So far, the prototype dipole magnet has been fabricated and tested. Through magnetic field optimization, measurement, and secondary trimming, the measurement results satisfy the physical requirements.

SYNOPSIS We present an optimal oxygen-blowing system with expert rules to improve the efficiency of refining low-carbon ferrochrome. A nonlinear model based on mass transfer theory, the principles of heat transfer, and the principles of high-temperature chemical reactions for refining low-carbon ferrochrome are established. The model is mainly used to control the oxygen supply rate during argon-oxygen top-bottom double-blown refining, thereby controlling the refining temperature and reducing the carbon content. Twenty production tests using a 5 t argon-oxygen refining furnace demonstrate the effectiveness of the system and reliability of the nonlinear model. A comparison of the model data with the experimental data shows that although the model fails to predict the silicon content in the final refined product, it can predict the contents of the main components at the refining end-point and the refining temperature accurately. Keywords: prediction model, end-point control, mass transfer theory, expert rules.

A control chart is typically examined based on the overall performance. This is crucial, as it will influence the final decision on the selection of a control chart. For this reason, the application of average run length (ARL) has been identified as the standard performance metric. In order to calculate ARL, practitioners must determine the size of the process shift in advance. Nevertheless, in practice, the process shift size cannot be predetermined, as practitioners may not have the requisite information associated with the process. Hence, in this work, the expected average run length (EARL) is employed as a performance metric for the unknown shift size in a process. This work evaluates the performance of a memory-type control chart, i.e. exponentially weighted moving average median (EWMA median) chart, with respect to ARL and EARL. The results indicate that, as long as the deterministic shift size is within the range of the process shift size, the chart’s performance is nearly the same, regardless of the use of the optimal pair based on minimizing ARL or EARL.

Purpose This study was conducted to investigate the feasibility and clinical potential of using the 3D printing technology (3DPT) versus typical strategy (thin-layer CT scan) for the treatment of complicated proximal humeral fractures (PHFs) in old people. Methods Sixty-six old patients age ranging from 61 to 76 years with persistent complicated PHFs were randomly assigned to two groups as per the controlled randomization table (34 cases in the test group and 32 cases in the control group). In the test group, 3DPT was applied to build the 3D facture model of a patient, according to the data acquired from the thin-layer CT scan and subsequently processed with Mimics software. This helped to confirm the diagnosis, design the individual operation plan, simulate the surgical procedures and perform the surgery as plan. In the control group, only thin-layer CT scan was applied for the design of the operation plan prior to the surgery. Here, parameters including surgery duration, blood loss volume during surgery, the number of fluoroscopy, time to union were statistically analyzed for two groups after the operation. The screw lengths designed before the surgery and measured during the surgery were compared. Results The 3D PHF model generated using 3DPT was able to provide the visual display and omni-directional observation of the direction and severity of the fracture dislocation, which facilitated preoperative diagnosis, operation planning and design, data measurement, preselection of internal fixator and surgical outcome simulation. According to the follow-up ranging from 12∼28 months for the 66 patients, the results showed no significant difference in time to union between the two groups ( P > 0.05). Apart from that, less surgery duration, less blood loss during surgery, less number of fluoroscopy can be observed compared with the control group ( P Conclusions In this study, 3DPT showed great clinical feasibility of the treatment of complicated PHFs. The 3D-print PHF model had the ability to clearly display the fracture and thus was useful to determine the fracture classification and the magnitude of fracture injury. It benefited surgeons to gain a better understanding of complicated PHFs, design a most suitable operation plan prior to surgery and facilitate the doctor-patient communication. This therefore enabled the reduction of intraoperative injury and the optimization of surgical outcomes.

Cervical cancer is one of the most prevalent malignancies in women worldwide. Therefore, the investigation about the molecular pathogenesis and related therapy targets of cervical cancer is an emergency. The objective of the present study is to investigate the effects of valproic acid (VPA), a histone deacetylase inhibitor, on the angiogenesis of cervical cancer. The effects and mechanisms of VPA on in vitro angiogenesis and vascular endothelial growth factor (VEGF) expression of human cervical cancer HeLa and SiHa cells were investigated. Our present study reveals that 1 mM VPA can significantly inhibit the in vitro angiogenic potential and VEGF expression of human cervical cancer HeLa and SiHa cells. Further, the transcription and protein levels of hypoxia inducible factor-1α (HIF-1α), and not HIF-1β, are significantly inhibited in VPA-treated cervical cancer cells. Over expression of HIF-1α can obviously reverse VPA-induced VEGF down regulation. VPA-treatment decreases the activation of Akt and ERK1/2 in both HeLa and SiHa cells in a time-dependent manner. The inhibitor of Akt (LY 294002) or ERK1/2 (PD98059) can inhibit VEGF alone and cooperatively reinforce the suppression effects of VPA on HIF-1α and VEGF expression. Collectively, our data reveal that the inhibition of PI3K/Akt and ERK1/2 signals are involved in VPA-induced HIF-1α and VEGF suppression of cervical cancer cells.

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Aim To evaluate the outcome of arthroscopy treatment using high-strength line in the treatment of tibial avulsion fracture of posterior cruciate ligament. Methods Both the avulsed bone block and the tibia bone bed were refreshed. The procedure was completed with the assistance of PCL director drill guide. The reduction and fixation using high-strength line were used to fix the avulsed bone by from posterior middle portal. Rehabilitation began early postoperatively. Results From January 2010 to June 2012, a total of 18 arthroscopically treated cases of PCL tibial avulsion fracture were retrospectively evaluated. Reduction of the avulsion fragment was obtained in all cases. 16 cases were followed up for 7–30 months (average 13.6), and 2 cases were out of follow-up. In the 16 followed patients, flexion and extension were back to normal within 6 weeks, and return to normal walk in 12 weeks. The bone healing was good without any vascular or nerve complications. All the patients regained the preinjury activity level. The mean score (and standard deviation) increased from 38.9 ± 4.9 points to 95.2 ± 3.8 points with the system of Lysholm, from 57.1 ± 10.3 points to 94.3 ± 4.4 points with the system of IKDC. Post-test displacement of KT3000 declined from 3.6 ± 0.39 to 1.1 ± 0.27 mm. Conclusion Arthroscopic vertical fixation by high-strength line is a simple, safe, reliable, and micro-invasive treatment to PCL tibial avulsion fracture. It is a kind of real all arthroscopic technique, and good for early postoperative rehabilitation. The total stability of the knee could be gained, and the second operation to remove the internal fixation is avoided.

Thyroid cancer is a very common form of endocrine system malignancy. To date, the molecular mechanism underlying thyroid cancer remains poorly understood. Studies of oncocytic tumors have led to a hypothesis which proposes that defects in oxidative phosphorylation (OX- PHOS) may result in a compensatory increase in mitochondrial replication and gene expression. As a result, mitochondrial DNA (mtDNA) mutation analysis has become a useful tool to explore the molecular basis of this disease. Among these mutations, mitochondrial transfer RNAs (mttRNAs) are the hot spots for pathogenic mutations associated with thyroid cancer. However, due to its high mutation rate, the role of mt-tRNA variants in thyroid cancer is still controversial. To address this problem, in this study, we reassessed seven reported mt-tRNA variants: tRNAAsp G7521A, tRNAArg T10411C and T10463C, tRNALeu(CUN) A12308G, tRNAIle G4292C and C4312T, and tRNAAla T5655C, in clinical manifestations of thyroid cancer. We first performed the phylogenetic conservation analysis for these variants; moreover, we used a bioinformatic tool to compare the minimum free energy (G) of mt-tRNA with and without mutations. Most strikingly, none of these variants caused the significant change of the G between the wild-type and the mutant form, suggesting that they may not play an important roles in thyroid cancer. In addition, we screened the frequency of the “pathogenic” A12308G alternation in 300 patients with thyroid cancer and 200 healthy controls. We found that there were five patients and three control subjects carrying this variant. It seemed that the A12308G variant may be a common polymorphism in the human population. Taken together, our study indicated that variants in mt-tRNA genes may not play active roles in patients with thyroid cancer.