Abstract: Chigger mites belong to the phylum Arthropoda, class Arachnida, sub-class Acari, order Parasitiformes, family Trombiculidae and Leeuwenhoekiidae, with a wide range of species. There are more than 3 700 known species of mites globally, of which 531 species in 46 genera from three sub-families have been recorded in China, and 320 species of chigger mites recorded from 3 subfamilies and 32 genera in Yunnan Province. At this stage, chigger mites are the only vectors of scrub typhus, with about 60 species worldwide being potential vectors. Six vectorial mite species have been confirmed in China, including Leptotrombidium deliense, L.scutellare, L.rubellum, L.sialkotense, L.kaohuense, L.insulare. Yunnan Province has reported five vectorial mite species, including the previously-mentioned five species except for L.sialkotense. The zoogeographic study divided Yunnan Province into 5 zoogeographic areas, namely, Central Hengduan Mountains subregion, Southern Hengduan Mountains subregion, Eastern Yunnan Plateau subregion, Western Yunnan Plateau subregion, Southern Yunnan Mountainous subregion. The Southern Hengduan Mountains subregion has the highest number of known genera and species of scrub typhus and the highest number of scrub typhus cases, with 216 species in 22 genera from 3 subfamilies, and all 5 species of vector scrub typhus were distributed. Southern Yunnan Mountain subregion has the least number of mite species, with 91 species in 12 genera from three sub-families, with L. scutellare being the dominant vectorial mite species across the province. Due to suitable natural geographic conditions in Yunnan Province, vectorial mites can propagate rapidly, leading to a large number of scrub typhus cases. According to statistics, the number of scrub typhus cases in Yunnan Province has rapidly increased, with 15.40 times, 20.64 times and 28.91 times more cases in 2016, 2017 and 2018 respectively than in 2006. Scrub typhus remains a serious public health problem in Yunnan Province, posing a threat to the health of the local population. Therefore, prevention and control efforts should continue to focus on the affected areas and the general public.

Objective To analyze and discuss the negative effects of atomization inhalation in mechanical ventilation patients in intensive care unit. Methods A retrospective study of all the mechanical ventilation patients in the general ICU of our hospital was carried out from Aprilto December 2015. The risk of multidrug-resistant organisms(MDROs)colonizationin the lower respiratory tract and ventilation associated pneumonia(VAP)in mechanical ventilation patients were analyzed. Results A total of 922 patients were monitored, 160 of whom had atomization inhalation, 92 for MDROs colonizationin the lower respiratory tract and 18 for VAP. The rates ofatomization inhalation in patients with and without MDROs colonizationin the lower respiratory tract were 30.4%(28/92)and 15.9%(132/830)with statistical difference (χ2=12.193, P=0.000). And those in patients with and without VAP were 50.0%(9/18) and 16.7%(151/904), with statistical difference (χ2=11.420, P=0.000). Atomization inhalation was the independent risk factor both of MDROs colonizationin the lower respiratory tract(OR=1.917, 95%CI1.163-3.159, P=0.011) and VAP(OR=4.613, 95%CI 1.773-12.002, P=0.000) in mechanical ventilation patients. Conclusions Atomization inhalation may increase the risk of MDROs colonizationin the lower respiratory tract and VAP in mechanical ventilation patients. Thus unnecessary and too frequent operations of atomization inhalation should be decreased.

Objective To observe whether bone marrow mesenchymal stem cells (MSCs) can promote the repair of IgA nephropathy and to explore its possible mechanism. Methods Sprague-Dawley rats were randomly divided into three groups which were MSCs injection group, normal saline(NS) infusion group and healthy control group. IgA nephropathy model was established by the improving method with BSA +SEB +CCl4 in former two groups. MSCs of SD rats were continuously cultured in vitro and identified with specific surface antigens by flow cytometry and osteogenic and adipogenic differentiation. MSCs were labeled with bromodeoxyuridine (BrdU) in vitro before transplanted. At 1st and 4th week after MSCs injection, the changes of body weight, urine protein, renal function, histopathology and IgA immunofluorescence were observed. MCP-1, TGF-β1 in urine were detected by ELISA. The expression of MCP-1, TGF-β1 in kidney were examined by RT-PCR. The cytokines and BrdU labeled MSCs were detected by immunohistochemistry to observe the disposition in kidney. Results At the end of the first week of MSCs transplantation, MSCs group urine protein (36.86±4.78) mg/24 h, serum creatinine (53.50±6.28) μmol/L, and the NS group urine protein (66.98±5.86) mg/24 h, serum creatinine (82.50±8.36) μmol/L, the differences between two groups were significant (P<0.05). At the same time, the content of MCP-1, TGF-β1 in urine and expression in renal tissue of MSCs group were obviously less than those of NS group (P <0.05). At the end of the 4th week, the body weight, histopatholngy, IgA immunofluorescence of MSCs group were remarkably improved as compared with those of NS group. The content of MCP-1, TGF-β1 in urine and expression in renal tissue, and renal pathological change in MSCs group had no significant differences as compared with those of healthy control group. As the time passed, the disposition of BrdU-labeled MSCs in kidney was taper. Conclusions MSCs injection contributes to renal repair in rat IgA nephropathy. The mechanism may partly depend on adjusting the excretion of cytokines in renal microenvironment and/or other functions rather than completely depend on their differentiation to renal cells.

Objective To construct genipin-crosslinked rat acellular spinal cord scaffolds and evaluate their enzymatic degradation rate,biomechanical properties and cytotoxicity.Methods Rat spinal cord scaffolds were decellularized by chemical extraction and chemically crosslinked with 5 g/L genipin solution.Micro-structure of the uncrosslinked and genipin-crosslinked acellular spinal cord scaffolds were observed by HE staining and scanning electron microscopy and properties of pore size,porosity,water ratio,and degradation rate in 2.5 g/L trypsin enzyme solution were examined.Ultimate tensile strength and elastic modulus of normal rat thoracic spinal cord,uncrosslinked and genipin-crosslinked acellular spinal cord scaffolds were determined on Instron mechanical testing instrument.Rat bone marrow mesenchymal stem cells were cultured in lixivium of uncrosslinked and genipin-crosslinked acellular spinal cord scaffolds and MTT assay for relative cell growth rate was test to evaluate the cytotoxicity of scaffolds.Results The uncrosslinked and the genipin-crosslinked acellular spinal cord scaffolds possessed a similar three-dimensional mesh-porous structure with a mean pore diameter about 30 μm and a porosity over 80％,but there was a statistical difference between the two groups(P ＞ 0.05).Water ratio of genipincrosslinked scaffolds was (229.7 ± 12.5) ％,far lower than (283.4 ± 11.2) ％ of uncrosslinked scaffolds (P ＜ O.05) ; genipin-crosslinked acellular spinal cord scaffolds had lower weight loss at each time point than the uncrosslinked acellular spinal cord scaffolds (P ＜ 0.05),but the stability in trypsin,ultimate tensile strength and elastic modulus of acellular spinal cord scaffolds were significantly enhanced by genipin-crosslinking (P ＜ 0.05).Furthermore,no obvious cytotoxicity was observed in the uncroslinked and genipin-crosslinked scaffolds.Conclusions Rat acellular spinal cord scaffolds present no obvious change in structure after genipin-crosslinking,but there is significant improvement in the biomechanical properties and ability against enzymatic degradation and no marked cytotoxicity.Hence,the genipincrosslinked scaffolds are promising in tissue engineering for spinal injury.

Objective:To study the effects of endothelial progenitor cells(EPCs)on the osteogenesis of bone marrow mesenchymal stem cell (BMSCs)sheet-implant complex.Methods:EPCs were added to the BMSC sheets,and the expression of osteogenesis-relat-ed genes was examined by real time PCR.Cell sheets were wrapped around implants to construct cell sheet-implant complexes and the complexes were subcutaneously transplanted into SCID mice.The complexes were harvested 8 weeks after operation and observed by micro-CT and histological examination.Results:The BMSC sheet with EPCs showed higher expression of Runx2,ALP,BMP2 and VEGF in the in vitro test;higher bone volume ratio,greater amount of new bone tissue and higher expression of Runx2 and BMP2 in the in vivo test.Conclusion:EPCs can improve the osteogenesis of BMSC sheet-implant complex.

To establish an HPLC method to determine osimertinib mesylate,Agilent ZORBAX Eclipse Plus C18 column (4.6 mm × 250 mm,5 μm) was used with a mobile phase consisting of methanol-buffer solution (20 mmoL/L NaH2PO4,pH 3.0 adjusted with 85％ H3PO4) (50 ∶ 50) at the flow rate of 1.0 mL/min.The detection wavelength was 210 nm,and the column temperature was kept at 35 ℃.The calibration curve was liner over the range from 50％ to 150％ of determination concentration (0.201 1-0.603 2 mg/mL,r =0.999 9).The limit of quantitation (LOQ) and limit of detection (LOD) were 0.32 μg/mL and 0.08 μg/mL,respectively.The contents of osimertinib mesylate in samples were 100.1％,99.5％ and 99.7％.Good chromatographic separation of osimertinib mesylate and its related substances,including synthetic impurities and degradation products,were obtained.The established HPLC method is specific,accurate,simple and durable,and could be used for the determination of osimertinib mesylate.

Objective To explore the CT manifestations of non-functional islet cell tumor(NFICT)Methods The findings of plain and enhancement CT scanning from 17 cases with NFICT,which were confirmed by the surgeries and pathological sections,were analyzed retrospectively.Ninty ml of non-ioniodine contrast reagent with 3ml/s injection flow rate was employed as the enhancer for measuring the arteriovenous double phase CT value of the pancreas and tumor.Results Tumors were found in all the cases who received CT scan.Compared with pancreatic substance in the CT plain scan,tumors with low density were found in 2 cases,tumors with mixed low density in 11 cases and tumors with isodensity in 4 cases.Local calcification in tumor was found in 5 cases.Various degrees of strengthening were showed in 17 cases with enhancement scanning.Obvious enhancement in arterial phase presented in 5 cases,moderate enhancement in 6 cases and slight enhancement in 6 cases.Conclusions CT plain scan of NFICT shows that the tumor margins are clear and some tumors have calcification.All tumors in the CT enhancement scanning show various degrees of enhancement,the persistent enhancement from arterial phase to portal vein phase is the characteristic manifestation of NFICT.

ObjectiveTo detect the mutations of GJB3 and GJB4 genes in two sporadic cases of erythrokeratodermia variabilis(EKV).MethodsGenomic DNA was extracted from two sporadic patients with EKV,their family members,and 100 normal human controls.All the exons and adjacent splice sites of GJB3 and GJB4 genes were amplified by PCR.Mutation scanning was carried out via direct bidirectional DNA sequencing.ResultsA G134C mutation was found at the GJB3 gene in patient 1,which caused a substitution of glycine by alanine at codon 45 (G45A).No mutation was found in the GJB4 gene in case 1 or GJB3 and GJB4 genes in case 2.ConclusionA missence mutation G45A in GJB3 gene is found in a patient with EKV.

According to the patient examination criterion and the demands of all related departments, the DSA digital subtraction workstation has been successfully designed and is introduced in this paper by analyzing the characteristic of video source of DSA which was manufactured by GE Company and has no DICOM standard interface. The workstation includes images-capturing gateway and post-processing software. With the developed workstation, all images from this early DSA equipment are transformed into DICOM format and then are shared in different machines.
Angiography, Digital Subtraction ; instrumentation ; methods ; Image Processing, Computer-Assisted ; Software Design ; User-Computer Interface

Objective: To explore the statistical differences of the vocational exhaustion positive rate among various occupational stress factors, occupational stress reaction, personality characteristics and relieving factors, to lay a foundation for reducing occupational stress of the medical staffs. Methods: 656 medical staffs in Yangzhong and Chifeng hospitals were included to conduct the evaluation of the occupational stress and job burnout, analyze the differences among the various factors by comparing them. Results: Various levels of vocational exhaustion positive rate among different occupational stress factors, occupational stress reaction, personality characteristics and relieving factors show statistical difference (P<0.05) . Among occupational stress factors, the vocational exhaustion positive rate of high level groups of conflict in groups was the highest (73.4%) , among occupational stress reaction, the vocational exhaustion positive rate of high level groups of body complain was the highest (80.4%) , among personality characteristics, the vocational exhaustion positive rate of low level groups of self-esteem was the highest (74.4%) , among relieving factors, the vocational exhaustion positive rate of high level groups of family support was the highest (76.4%) . Conclusion The vocational exhaustion rate of medical staffs show very high in the profession, comprehensive factors should be considered to create harmonious working atmosphere and to reduce vocational exhaustion positive rate of the medical staffs, to reduce the positive rate of vocational exhanstion in medical staffs.