BACKGROUND: Due to dentition defect, dentition loss, periodontal disease, trauma and tumor, many patients have to face insufficient buccal-lingual mandibular width. At present, there is no consistent conclusion in suitable peri-implant buccal-lingual mandibular width. OBJECTIVE: To investigate the stress of implant-bone interface with three-dimensional finite element method, in order to evaluate buccal-lingual mandibular width suitable for implants. METHODS: Classes Ⅰ and Ⅲ mandible implant models (the buccal-lingual width of implant neck region was 1, 1.5, 2, 2.5, 3 and 3.5 mm) were loaded with 200 N forces vertical y and at 60° oblique. Then, the stress and strain in the implant-bone interfacial were analyzed. RESULTS AND CONCLUSION: Almost 2 mm or more than 2 mm of mandible bone width could result in good stress distribution in implant-bone interface. The stress distribution of oblique loading was much greater than that of vertical loading. Proper quantity of peri-implant mandibular width is good for stress distribution in implant-bone interface. In the clinical treatment, the oblique loading should be avoided or reduced.

BACKGROUND:Due to good function and aesthetic effect, implant dentures become prevalent in osteoporotic patients with missing teeth. However, whether osteoporosis is a contraindication of dentures as wel as effects of osteoporosis on the bone-implant integration have been not ful y understood.
OBJECTIVE:To compare the levels of alkaline phosphatase, bone mineral density and implant stability in patients with osteoporosis and non-osteoporosis, and to explore whether the osteoporotic patients can achieve good prognosis. METHODS:Forty patients undergoing implant dentures in the Department of Prosthodontics, the First Affiliated Hospital of Xinjiang Medical University since February 2015 were enrol ed, and al otted to experimental (osteoporosis) and control (non-osteoporosis) groups (n=20 per group).
RESULTS AND CONCLUSION:The levels of salivary alkaline phosphatase, bone mineral density and initial implant stability in the experiment and control groups both were lower than those before surgery. There were significant
differences in the implant stability quotient at 1 and 3 months and immediately after implantation between groups. These results indicate that osteoporotic patients undergoing implant surgery can achieve a good prognosis that is similar with non-osteoporosis ones.

BACKGROUND:Fol owing physicochemical treatment and high-temperature calcinations, heterogeneous
biological bone becomes a ceramic-like heterologous bone forming a similar structure to the human bone that is a natural network pore structure, which is conducive to seed cel adhesion and proliferation.
OBJECTIVE:To observe the feasibility of constructing tissue-engineered bone through combination of sintered bone and bone marrow mesenchymal stem cel s to repair alveolar defects.
METHODS:Sheep bone marrow mesenchymal stem cel s as seed cel s were combined with the high
temperature sintered bone as scaffold materials to construct tissue-engineered bone. Under general anesthesia, sheep bilateral mandibular first premolars were removed in batches, the alveolar ridge space between the distal root and mesial root of the second premolar to form a bone defect area of 5 mm×5 mm×5 mm. Twelve
experimental sheep were equal y randomized into tissue-engineered bone group and sintered bone group, which were implanted with tissue-engineered bone and sintered bone, respectively, at the left surgical area of the
mandible. The right surgical area was considered as blank control group.
RESULTS AND CONCLUSION:After high-temperature calcinations, the sintered bone was chalk in color, exhibiting a porous structure as the natural cancel ous bone. The porosity was (66.10±1.32)%, and the pore size was between 137.44μm and 538.72μm. After 24 hours of bone marrow mesenchymal stem cel s inoculated to the sintered bone, a large number of cel s are visible adherent to the scaffold;up to day 7, extracel ular matrix was secreted and there was no clear boundary between the cel s and the matrix. X-ray films showed that the tissue-engineered bone and pure sintered bone implants were embedded in the surgical area, and there was a low-density shadow at the edge of the sintered bone. Hematoxylin-eosin staining showed bone trabecular formation at the experimental side, but no obvious bone formation at the control ed side. Tissue-engineered bone prepared by bone marrow mesenchymal stem cel s and sintered bone can better repair sheep alveolar bone defects, which is an ideal seed cel and scaffold material for smal range bone defects.

High-affinity α-glucosidase inhibitors were screened from Cichorium glundulosum Boiss.et Hout seed (CGS) extract by ultra-filtration affinity-liquid chromatography-mass spectrometry (UF-LC-MS) and molecular docking.By taking 4-nitrobenzene-α-D-glucopyranoside (PNPG) as substrate and acarbose as positive control to evaluate the inhibitory activity of CGS extract, IC50 of acarbose and CGS extract were 0.003 mg/mL and 0.447 mg/mL, respectively.Meanwhile, 4 compounds from CGS extract by UF-LC-MS were screened and identified.Then by using autodock software, the compounds that combined with α-glucosidase were well screened out, including chlorogenic acid and isochlorogenic acid A.The inhibitory activity of chlorogenic acid and chlorogenic acid A against α-glucosidase was verified in vitro.The results showed that the inhibitory activity of the compounds toward α-glucosidase presented the sequence of acarbose>isochlorogenic acid A>chlorogenic acid.The inhibition rate of isochlorogenic acid A was close to acarbose.The experimental results illustrated that UF-LC-MS and molecular docking could be used to screen high affinity enzyme inhibitors from CGS.

Objective: To understand the trend of changes of hygiene status in the teaching environment among primary and secondary schools in Beijing City during 2016-2020, so as to provide basis for further improving the teaching environment and campus hygiene conditions in primary and secondary schools. Methods: A proportional systematic sampling method covered over 50% of schools selected annually in Beijing from 2016 to 2019, and 34% were selected in 2020. Two representative classrooms were selected from each selected school for testing based on their structure and other factors, with 6 196 classrooms supervised, from 2016 to 2020,1 330,1 312,1 384,1 322,848 classrooms were monitored for each year. Results: From 2016 to 2020, the overall lighting qualification rate of classrooms (lighting coefficient 72.8%, window to floor area ratio 41.8%, rear wall reflectance ratio 42.2%, blackboard reflection ratio 37.4%), the overall qualification rate of average blackboard illumination and uniformity (50.6%, 34.9 %), and the overall qualification rate of desk and chair allocation (58.6%) were all below 80%. The overall qualification rate of per capita classroom area (87.5%), blackboard size (83.2%), average desk illumination ( 80.1% ), average desk illumination and uniformity (82.9%), the distance between lamp and desk (99.1%), carbon dioxide ( 86.6% ), temperature (84.9%), and noise (96.6%) were all above 80%. The following indicators, blackboard size, the distance between lamp and desk, average blackboard illumination, lighting coefficient, blackboard reflectance, rear wall reflectance, carbon dioxide, temperature, and noise ( χ 2=78.38, 9.71, 11.76, 320.59, 37.63, 58.45, 236.45, 1 347.56, 101.97), had statistically significance between years. Among those indicators, the qualified rates of blackboard size, blackboard reflectance, lighting coefficient, and noise had been increasing year by year ( χ 2 trend =69.98, 15.82, 240.02, 5.77) ( P <0.05). The qualified rates of per capita classroom area, window to floor area ratio, and blackboard reflection ratio in primary schools (81.6%, 39.8%, 36.3%) were all lower than those in secondary schools (94.9%, 44.5%, 40.3%) ( χ 2=246.32, 12.03, 10.51, P <0.05). The qualified rates of blackboard size, average blackboard illumination, average blackboard illumination and uniformity, and desk and chair allocation (89.3%, 55.6% , 36.0%, and 60.2%) were all higher than those in secondary schools (75.4%, 44.1%, 33.3%, and 56.5%) ( χ 2=209.33, 78.41, 4.44, 8.22) ( P <0.05). The qualified rates of average desk illumination and uniformity, average blackboard illumination, rear wall reflectance ratio, desk and chair allocation, carbon dioxide, temperature, and noise indicators in urban area (82.9%, 84.1% , 51.9%, 45.0%, 60.9%, 91.2%, 89.5%, 97.8%) were all higher than those in suburban area (77.3%, 81.7%, 49.2%, 39.5%, 56.3%, 82.3%, 80.4%, 95.5%) ( χ 2=31.16, 6.28, 4.36, 16.40, 13.39, 105.29, 98.23, 24.66， P <0.05). The qualified rates of the distance between lamp and desk, lighting coefficient, window to floor area ratio, blackboard size, blackboard reflection ratio, average blackboard illumination and uniformity, and per capita classroom area in urban areas (98.8%, 65.2%, 34.3%, 76.7%, 35.9%, 30.1%, 84.6%) were all lower than those in suburban areas (99.4%, 81.4%, 49.8%, 89.7%, 40.2%, 39.6%, 90.3%) ( χ 2=6.80, 171.67, 132.43, 188.46 , 12.45, 60.28, 44.82) ( P <0.05). Conclusions The main problems in the teaching environment of schools in Beijing are classroom lighting, as well as desk and chair allocation. The findings suggest technical rationality and operability of relevant standard should be considered when under revision, and standard training and supervision management should be strengthened, with the aim of teaching environment improvement.

Objective: To explore the association between reading and writing posture with the occurrence of myopia in Chinese children and adolescents, so as to provide a reference for reducing its prevalence among primary and secondary school students. Methods: Using data from the 2020 survey on the current status of hyperopia reserve in primary and secondary school students from six provinces/cities, namely Beijing, Zhejiang, Chongqing, Shaanxi, Liaoning, and Henan selected by multi stage stratified cluster probability sampling method during November 2020 to June 2022. A total 16 782 students who completed the optometry examination of cycloplegia according to the Children and Adolescents Myopia Screening Standard and questionnaire survey were included for analyzing analyze the association between reading and writing posture with myopia. Results: The overall detection rate of myopia among primary and secondary school students was 45.7%, of which 35.0% were primary school students, 84.1% junior high school students, and 90.4% senior high school students. Poor reading and writing posture was found in 73.6% of primary and secondary school students. Adjusting for confounding factors such as gender, school period, region, outdoor time every day, and whether parents were myopic, the results of the multilevel Logistic regression showed that the following factors were positively correlated with myopia:poor reading and writing posture ( OR=1.17, 95%CI =1.07-1.28), never/occasionally reading and writing with a reading distance which was more than one foot away between the eyes and book ( OR=1.28, 95%CI=1.08-1.53, OR=1.23, 95%CI = 1.08- 1.40), teachers occasionally reminding the child of their reading and writing posture ( OR=1.13, 95%CI =1.01-1.25), and often/always reading and writing while lying down or with the face on the arm ( OR=1.15, 95%CI=1.01-1.32, OR=1.46, 95% CI = 1.17-1.82), always reading and writing with the head in the hand ( OR=1.56, 95%CI =1.20-2.01). Further, a negative correlation was detected between myopia and parents occasionally reminding their children of their reading and writing posture ( OR= 0.85 , 95%CI =0.76-0.96) ( P <0.05). Conclusion Poor reading and writing posture is a risk factor for the development of myopia in primary and secondary school students, and interventions for reading and writing posture need to be strengthened to reduce the occurrence of myopia among primary and secondary school students.

Phage display random heptapeptide library was screened with recombinant P37 in this study. The positive phage clones were identified by ELISA and were sequenced, and the amino acid sequences of the polypeptides displayed on phage were deduced. After GST-polypeptides fusion protein was constructed and expressed, its binding to P37 was determined by GST-pull down and Western blot. After 4 rounds of bio-panning, the enriched positive phage clones were identified by ELISA. Eighteen positive phage clones were sequenced and the peptide sequences were as follows. ACAPKPPWLC (12/18), RPLSIDPWSPHL (3/18), RPLSNDPWSPHL (1/18), QNMMSPIEGVRI (1/ 18) and WAPEKDYMQLMK (1/18). The results from GST-pull down and Western blot showed that peptide RPLSIDPWSPHL could interact with P37. The study will be helpful for identifying the protein reacting with P37.
Animals ; Bacterial Proteins ; metabolism ; Base Sequence ; Molecular Sequence Data ; Mycoplasma hyorhinis ; metabolism ; Oligopeptides ; metabolism ; Peptide Library ; Protein Binding ; Swine

Since the first operational definition of cognitive frailty was proposed by the expert consensus group of the International Academy of Nutrition and Aging and the International Association of Gerontology and Geriatrics in 2013, frailty and neurocognitive assessment has become the standard diagnostic tool.Since then, the reported prevalence in the literature for cognitive frailty in community-dwelling elderly people vary by dozens of times, as a result of different scales and diagnostic cut-off points, seriously affecting health decision-making.This article reviewed the current literature with a focus on the re-recognition of the clinical significance of cognitive frailty, the limitations of existing assessment tools for diagnosis, and possible solutions in the future.

Objective To investigate the correction between the levels of vascular endothelial growth factor (VEGF), serum amyloid A (SAA), hypersensitive C-reactive protein (hs-CRP) and acute cerebral infarction (ACI), and to provide the basis for the diagnosis and treatment of ACI.Methods A total of 76patients with ACI in the hospital from August to October 2017were selected as ACI group.In addition, 32healthy subjects underwent physical examination in the same period in this hospital were selected as negative control group (NC group).The levels of SAA and hs-CRP were detected by nephelometry, while the level of VEGF was measured by enzyme-linked immunosorbent assay (ELISA).The differences of detection indexes between two groups were compared, and the diagnostic value of each index and the combined test were evaluated with the Youden index.Results The levels of SAA, hs-CRP and VEGF in ACI group, were significantly higher than those of NC group (P＜0.01).The levels of VEGF was positively correlated with SAA and hs-CRP (r=0.434and0.631, P=0.000and 0.000).The optimal diagnostic critical points of VEGF, SAA and hs-CRP in the diagnosis of ACI were 161.93pg/mL, 3.81mg/L and 4.63mg/L, and the sensitivities were 93.55％, 65.91％and64.44％, the specificities were 60.00％, 93.75％and 90.32％, respectively.Combined detection with hs-CRP and VEGF was superior to single index detection and other joint detection.The sensitivity, specificity and Youden index of combined detection with hs-CRP and VEGF were 96.67％, 95.65％and 0.92respectively.Conclusion The levels of VEGF, SAA and hs-CRP increase in patients with ACI, and they play important roles in the diagnosis of ACI.VEGF are positively related to SAA and hs-CRP, and there may be an synergistic effect exist.VEGF may be involved in the pathological process of cerebral infarction.The combined detection of hs-CRP and VEGF is of high clinical value in the diagnosis of cerebral infarction.