Background The job content of aircraft maintenance workers is complex, with high intensity and high requirements, and they are prone to work-related musculoskeletal disorders (WMSDs), but related research is relatively rare. Objective To investigate the positive rate of WMSDs among aircraft maintenance workers, evaluate ergonomic load, and analyze the risk factors of WMSDs. Methods We used a self-compiled questionnaire for WMSDs and the Quick Exposure Checklist (QEC) to investigate the basic situation, positive rate of WMSDs, and the ergonomic load of 2271 male maintenance workers in 6 departments of an aircraft maintenance company, including airline maintenance, overall overhaul, accessory/landing gear overhaul, engine overhaul, product customization, and power assist. We used a logistic regression model to analyze the risk factors of WMSDs in the neck, shoulder, hand/wrist, and lower back. Results The positive rate of WMSDs in the past 12 months was 70.4% (1598/2271) and the positive rate of WMSDs in different body parts ranged from 6.6% to 49.5%, with the top three parts of lower back, neck, and knee, respectively. There were statistically significant differences in the positive rate among different departments (P<0.05). The average QEC scores for neck, hand/wrist, and back (static) were moderate, while those for shoulder and back (dynamic) were high, and the body part specific positive rate of WMSDs increased with the increase of ergonomic load level. Working years (5-<10 years, ≥20 years), working with back flexed or twisted or side bent (moderately, excessively), high maximum force level exerted by one hand, and feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of lower back pain (OR=1.486, 1.505; 2.151, 3.769; 1.637; 2.110, 2.407; 1.637, 1.794; P<0.05). Working years (15-<20 years, ≥20 years), working with head/neck bent or twisted (occasionally, continuously), feeling difficult (sometimes) and stressful (very) while working were associated with higher risks of neck pain (OR=1.731, 1.586; 3.732, 8.341; 1.633; 1.696; P<0.05). Working years (15-<20 years, ≥20 years), working with hands in a high position (at shoulder or above), very frequent shoulder/arm movements, feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of shoulder pain (OR=1.587, 1.709; 1.299; 1.521; 1.643, 2.239; 1.659, 1.977; P<0.05). Working with wrist at deviated or bent angle, high repetition of similar movements, feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of hand/wrist pain (OR=1.692; 1.670; 1.827, 2.884; 2.190, 2.625; P <0.05) . Physical exercise after work (≥3 times·week⁻¹) was associated with a lower risk of neck pain (OR=0.582, P<0.05). Shift workers were at a lower risk of shoulder pain and hand/wrist pain (OR=0.737 and 0.554, P<0.05). Conclusion The high positive rate of WMSDs symptoms among aircraft maintenance workers is related to individual, occupational ergonomic, and psychological factors, and active prevention and intervention should be taken.

Background With the rapid development of China's express delivery industry, small parcel couriers generally report overtime, excessive intensity, and high work load, and are at a high risk of developing work-related musculoskeletal disorders (WMSDs). Using questionnaires to conduct research on WMSDs-associated postures may contain unavoidable subjectivity, and the simulation methods can quantitatively evaluate WMSDs, boasting advantages such as high efficiency and low cost, and become a research development trend. Objective To conduct ergonomic evaluation of typical postures of express couriers handling small parcels using a simulationmethod. Methods SolidWorks software was used to establish a geometric model of a parcel (530 mm depth × 290 mm width × 370 mm height), a geometric model of an express carriage (1.4 m depth × 0.9 m width × 1.17 m height), and a geometric model of a delivery truck (1.7 m height). These models were imported into Jack software, and the weight of parcel was set at 20 kg. The digital model of a male express courier was established in Jack software. A typical parcel handling task was defined as standing on one side of the express carriage and bimanually placing parcels at four different heights (top, upper half, middle, and bottom of the carriage) combined with three horizontal positions (outer side, center, and inner side of the carriage). The visual field and reach zones tools in Jack software were used to determine whether the parcels can be seen and touched by the express courier, and determine the operational posture of the express courier at their ends of motion ranges. The Ovako working posture analysis system (OWAS) and rapid upper limb assessment (RULA) tools in Jack software were used to evaluate postures applied at typical vertical and horizontal distances. Results The maximum horizontal and vertical gaze fields effectively covered the area where the parcels were located, but some areas were not within the optimal field of view. When the horizontal distance between the parcel and the express courier exceeded 48 cm, the express courier was not able to directly reach it and had to adjust his standing position or posture to perform the task. The OWAS analysis found that when the express item was placed at the top, upper section, or middle of the carriage, the risk level of the courier's work posture was level 1, suggesting a normal posture. When the parcel was placed at the inner side bottom of the carriage, the courier needed to bend his knees and lower back, and the highest risk level for the posture was level 3, which had harmful effects on the musculoskeletal system, and correctiveactions were required as soon as possible. The other two work postures placing the parcel elsewhere in the bottom were graded level 2, which may cause harm to the musculoskeletal system , and corrective actions were required in the near future. The RULA analysis found that the risk of the posture was level 2 for handling the parcel in the upper or middle of the carriage, and level 3 for handling the parcel at the top or bottom of the carriage. When the parcel was placed at the bottom of the carriage, as the horizontal distance between the express item and the courier increased, the risk of posture increased to level 3 or above, and the risk reached level 4 for the parcel located at the innermost side of the carriage. Conclusion There is a significant risk of WMSDs in manually handling parcels at different heights and horizontal positions. The risk levels of associated postures are elevated from low to high following the express item pleased at the middle, upper, bottom, and top of the carriage and the extension of horizontal distances, if the express item is placed at the bottom of the carriage, between the courier and the parcel. By installing doors on both sides of the express delivery carriage, it is possible for the express courier to adjust his standing position and provide a vertical motion range, ensuring best visual field and reach zones.

Objective:To retrospectively analyze the treatment status of tyrosine kinase inhibitors (TKI) in newly diagnosed patients with chronic myeloid leukemia (CML) in China.Methods:Data of chronic phase (CP) and accelerated phase (AP) CML patients diagnosed from January 2006 to December 2022 from 77 centers, ≥18 years old, and receiving initial imatinib, nilotinib, dasatinib or flumatinib-therapy within 6 months after diagnosis in China with complete data were retrospectively interrogated. The choice of initial TKI, current TKI medications, treatment switch and reasons, treatment responses and outcomes as well as the variables associated with them were analyzed.Results:6 893 patients in CP ( n=6 453, 93.6%) or AP ( n=440, 6.4%) receiving initial imatinib ( n=4 906, 71.2%), nilotinib ( n=1 157, 16.8%), dasatinib ( n=298, 4.3%) or flumatinib ( n=532, 7.2%) -therapy. With the median follow-up of 43 ( IQR 22-75) months, 1 581 (22.9%) patients switched TKI due to resistance ( n=1 055, 15.3%), intolerance ( n=248, 3.6%), pursuit of better efficacy ( n=168, 2.4%), economic or other reasons ( n=110, 1.6%). The frequency of switching TKI in AP patients was significantly-higher than that in CP patients (44.1% vs 21.5%, P<0.001), and more AP patients switched TKI due to resistance than CP patients (75.3% vs 66.1%, P=0.011). Multi-variable analyses showed that male, lower HGB concentration and ELTS intermediate/high-risk cohort were associated with lower cytogenetic and molecular responses rate and poor outcomes in CP patients; higher WBC count and initial the second-generation TKI treatment, the higher response rates; Ph + ACA at diagnosis, poor PFS. However, Sokal intermediate/high-risk cohort was only significantly-associated with lower CCyR and MMR rates and the poor PFS. Lower HGB concentration and larger spleen size were significantly-associated with the lower cytogenetic and molecular response rates in AP patients; initial the second-generation TKI treatment, the higher treatment response rates; lower PLT count, higher blasts and Ph + ACA, poorer TFS; Ph + ACA, poorer OS. Conclusion:At present, the vast majority of newly-diagnosed CML-CP or AP patients could benefit from TKI treatment in the long term with the good treatment responses and survival outcomes.

Objective:Based on the AAPM TG-263, a Content-Based Standardizing Nomenclatures (CBSN) was proposed to explore the feasibility of its standardization verification for organs at risk (OAR) of nasopharyngeal carcinoma (NPC).Methods:The radiotherapy structure files of 855 patients with nasopharyngeal carcinoma (NPC) receiving intensity-modulated radiotherapy (IMRT) from 2017 to 2019(15 of whom showed clinical anomalous structures) were retrospectively collected and processed. The Matlab self-developed software was used to obtain the image position, geometric features, first-order gray histogram, and the Gray-level Co-occurrence Matrix′s texture features of the OAR contour outlined by the doctor to establish the CBSN Location Verification model and CBSN Knowledge Library. Fisher discriminant analysis was employed to establish a CBSN OAR classification model, which was evaluated using self-validation, cross-validation, and external validation, respectively.Results:99%(69/70) of the simulated anomalous structures were outside the 90% reference range of the CBSN Knowledge Library and the characteristic parameters significantly differed among different OARs (all P<0.001). The accuracy rates of self-validation, cross-validation and external verification of the CBSN OAR classification model were 92.1%, 92.0% and 91.8%, respectively. Fourteen cases of clinical abnormal structures were successfully detected by CBSN with an accuracy rate of 93%(14/15). In the simulation test, the accuracy of the left and right location verification reached 100%, such as detecting the right eye lens named Len_L. Conclusion:CBSN can be used for OAR verification of NPC, providing reference for multi-center cooperation and standardized radiotherapy of NPC patients.

Objective To discuss the application of self-developed novel 16-slice mobile CT head scan.Methods A total of 391 patients were performed 16-slice mobile CT scan:145 were scanned in the emergency department,156 in the neurosurgical ICU,55 in the operated room,and 35 in the ambulance vehicle.Sixty-eight patients were with brain injury,122 were with cerebral hemorrhage,120 were with cerebral infarction,59 were with brain tumors,and 22 were with hemifacial spasm.Thirty-five patients were randomly selected from 391 patients and 8-slice mobile CT head scan was performed on them,which included 12 with brain injury,6 with cerebral hemorrhage,12 with cerebral infarction,3 with brain tumors and 2 with hemifacial spasm.The resolution,imaging quality,radiation doses,power consumption and performance stability of novel 16-slice mobile CT and 8-slice mobile CT head scan were compared.Results The resolution line pairs of brain tissues were 91 p/cm by 16-slice mobile CT and 71 p/cm by 8-slice mobile CT,respectively.The imaging quality of the two kinds of mobile CT head scans was high level to the clinic diagnostic criteria.The radiation dose of 16-slice mobile CT were 40.43 mGy,which decreased by 51.01％ as compared with that of 8-slice mobile CT (82.52 mGy).The personal power consumption of 16-silce mobile CT (0.29 kW· h) decreased by 38.30％ as compared with those of 8-layer mobile CT (0.47 kW· h).The 16-slice mobile CT kept regularly,while 8-slicer mobile CT stopped to work twice during clinical trial.Conclusion The 16-slice mobile CT scan has high resolution,fine imaging quality,low radiation dose,small power consumption and stable working performance.

Objective To study the value of CT perfusion imaging(CTPI)on brain hemodynamic of the aged with cerebral infarction. Methods The 48 patients who were doubted with cerebral infarction underwent 16-slice CT plain scanning and CTPI within 24 hours of onset. The cerebral blood flow(CBF), mean transit time(MTT)and time to peak(TTP)of contrast-medium in region of interest(FOV)were used as brain hemodynamic parameters in comparation with contralateral regions. All cases were followed up with MRI after 3-10 days. Results Ischemia lesion was found on CT plain scanning in 40.9% of patients, while 93.2% of patients showed abnormal perfusion on CTPI. The sensibility of CTPI in identifying ischemia area was 93.2%, and the specificity was 100%. CBF in research area was significantly reduced, MTT and TTP were remarkably increased in contrast to counterparts(P＜0.01). Conclusions CT perfusion imaging can sensitively reveal the hemodynamic condition of cerebral ischemia, which could provide the important information for early diagnosis and treatment of the elderly with brain infarction.

Both phytase and endoglucanase are additives in feed for mono-gastric animal known for their effects. Recombinant vector pPICZalpha-EG was constructed and transformed to GS115-phyA, a Pichia pastoris strain that had integrated with phytase gene, generating GS115-phyA-EG. Both phytase and endoglucanase activities in the supernatant were determined after methanol induction of GS115-phyA-EG. Phytase and endoglucanase activity reached 39.4% and 56.2% activity compared to GS115-phyA and GS115-EG, respectively. Properties of the mixed enzyme suggest that the optimal temperature and pH value be 55 degrees C and 5.5 respectively. Both phytase and endoglucanase showed greater than 80% activity across temperature ranges 45 degrees C to 55 degrees C and pH ranges 4.5 to 5.5. Expressing more than one enzyme in one system could save time and money during induced expression, and the mixed enzyme might apply for treating forge before feeding with poultry.
6-Phytase ; biosynthesis ; genetics ; Cellulase ; biosynthesis ; genetics ; Genetic Vectors ; Pichia ; enzymology ; genetics ; Recombinant Proteins ; biosynthesis ; genetics

Objective:To investigate the effect of gemcitabine on myeloid derived suppressor cells (MDSC) in the spleen of B lymphoma cell-bearing mice, and the therapeutic effect of gemcitabine combined with intratumoral injection of dendritic cells (DCs) in treatment of large B lymphoma. Methods: BALB/c mice were inoculated subcutaneously with B lymphoma A20 cells; large tumors were formed 30 d after inoculation. Gr-1~+ CD11b~+ MDSC proportion in the spleen was analyzed by flow cytometry before and after gemcitabine treatment. Splenic MDSC sorted by immunomagnetic beads was further treated with gemcitabine, and then the apoptosis of MDSC was examined by Annexin-V/PI staining. Tumor growth and survival time of A20 tumor-bearing mice were observed after treatment with gemcitabine and intratumoral injection of DCs. Results: Splenic Gr-1~+ CD11b~+ MDSC ratio in A20 cell-bearing mice was 10 times higher than that in the normal mice. Gemcitabine induced apoptosis and necrosis of purified MDSC in vitro in a time-dependent manner. The percentage of MDSC in the spleen of A20 tumor-bearing mice was decreased after injection of a single dose of gemcitabine. Gemcit-abine or intratumoral injection of DCs alone inhibited growth of tumor to a certain degree, with the mean survival periods of mice in the gemcitabine, DCs, and untreated groups being (48.8±3.6) d, (47.2±7.4) d, and (38.8±2.2) d, respectively. Gemcitabine chemotherapy combined with intratumoral DC injection resulted in continuous shrink of the tumors, and 60% of the mice survived for more than 90 d. Conclusion: Gemcitabine can effectively eliminate splenic MDSC in tumor-bearing mice. Gemcitabine chemotherapy and DCs immunotherapy can work synergistically in the treat-ment of huge lymphoma. These results provide an experimental basis for the comprehensive chemotherapy and immunotber-apy of relapsed or refractory lymphoma.

The application of resonance charging circuit to electro-hydraulic impulse apparatus for treating wastewater is introduced in this paper.The circuit permits the graduating increase of current without influence from time.The unique change of voltage on capacitor is favorable for the recovery of electric strength of electro-hydraulic impulse apparatus.The theory and design method of resonance charging circuit are provided.

Objective To investigate the effectiveness,safety of the percutaneous transluminal angioplasty and stenting(PTAS) in the management of the vertebrobasilar stenosis.Methods From April 2003 to June 2004,the PTAS was performed in 28 patients with the vertebrobasilar stenosis.Results Among the 28 patients,the unilateral significant stenosis of the dominant vertebral artery was found in 18 patients,the bilateral stenosis of the vertebral artery in 4 patients,the tandem stenosis of the vertebral artery in 1 patient,the stenosis of the basilar artery in 2 patients.According to Mori's division,the type A occurred in 24 patients,the type B in 3 patients,the type C in 1 patient.The successful rate of stent implantation was 100% without any serious complication.Twenty-eight patients underwent PTAS with a mean pre-procedural vertebrobasilar stenosis of 81.3% and the residual stenosis was less than 10%.Over a mean 6-month follow-up in 17 patients,according to Malek's scale,the scale 1 was in 15 patients,the scale 2 in 2 patients.No restenosis was in 3 patients by the cerebral angiography.Conclusion PTAS in the management of the vertebrobasilar stenosis is a safe and effective method.Meanwhile,PTAS may alleviate the vertebrobasilar ischemia and prevent stroke of the vertebrobasilar system.