Effects of hourly precipitation and temperature on ambulance response time.

BACKGROUND: Longer ambulance response time (ART) delaying treatment would worsen conditions of seriously ill or injured patients, but limited evidence is available on the effects of weather factors on ART. This study aims to assess precipitation- and temperature-ART associations and their potential lagged effects using a novel modeling strategy. METHODS: Based on 779,156 emergency records during 2010-2016 from the whole population in Shenzhen, China, we creatively combined quantile regression with distributed-lag nonlinear models to examine the non-linear and lagged effects of hourly precipitation and temperature on ART at the 50th and 90th percentiles. RESULTS: A linear precipitation-ART association with a delay of 9.01 (95%CI, 7.82-10.20) seconds at median ART for a 1 mm increase in hourly precipitation, and the effects lasted for 5 h with the greatest effect at the current hour. A two linear thresholds temperature-ART association revealed 1 °C decrease below 19 °C caused 1.68 (95%CI, 0.92-2.44) seconds delay in total ART over lag 0-7 h, and 1 °C increase above 24 °C caused 2.44 (95%CI, 1.55-3.33) seconds delay. The hourly call volumes exceeding 54 calls caused 8.79 (95%CI, 8.71-8.86) seconds delay in total ART for 1 more call, but not affected the effects of weather factors. The internal ART suffered more from the hourly call volumes, while the external ART suffered more from precipitation and temperature. The effects were apparently greater on ART at the 90th percentile than median. CONCLUSIONS: Precipitation and temperature are independent risk factors for ambulance services performance, and their lagged effects are notable. The external ART and patients with long ART are vulnerable. More attention should be paid to weather and ART, and these findings may have implications for effective policies to reduce ART to protect public health.

Development and validation of a pre-scoring system for nonspecific low back pain among general population in Guangzhou: a cross-sectional study.

BACKGROUND: Nonspecific Low Back Pain (NLBP) is a common disease with a low cure rate and significant impact on the population. This study aimed to develop and validate a pre-scoring system for identifying the risk of suffering from NLBP among the general population in Guangzhou. METHODS: A total of 1439 eligible subjects were surveyed in Guangzhou by stratified random sampling and was divided randomly into the development dataset (69.6%) and validation dataset (30.4%) subsequently. Based on the development dataset, potential associated factors (average exercise times weekly, the intensity of daily work, etc.) with NLBP were tested by the sequential logistic regression, and a pre-scoring system was formulated with Sullivan's method and graded afterward. The internal validity of the system was assessed by AUC and calibration plot, and the external validation was performed in the validation dataset. RESULTS: The prevalence rates of NLBP in the development dataset and the validation dataset were 12.97 and 13.27%, respectively. Age, BMI, average exercise times weekly, gender, educational level, the intensity of daily work, place of residence, monthly income, overall evaluation of health condition and physiology health were identified as significant factors. The total risk score ranged from 0 to 38, which was split into three risk grades: low risk (0 to 18), intermediate risk (19 to 22) and high risk (23 to 38). The pre-scoring system had an adequate calibration and a good discriminating ability with bootstrap-corrected AUC equaling 0.861 in the development dataset and 0.821 in the validation dataset. CONCLUSIONS: A pre-scoring system that could help clinicians to assess the risk of NLBP in the general population was validated. Further validation of the system in a new population or prospective cohort study is suggested.

Risk factors associated with the detection and missed diagnosis of colorectal flat adenoma: a Chinese multicenter observational study.

OBJECTIVES: Flat colorectal adenomas have a high risk of malignancy; however, their detection is often difficult due to their flat morphology. In this retrospective, large-scale study, we investigated the prevalence and characteristics of flat adenomas in a population in China. METHODS: We analyzed the data collected for 16951 consecutive patients who underwent colonoscopy at four participating hospitals between September 2013 and September 2015. All colonoscopies were performed without magnification. RESULTS: Among the 1,6951 patients, 2938 (17.3%) had adenoma and 796 (4.7%) had flat adenomas. The detection of flat adenoma showed a weak correlation with the detection of adenoma (r = 0.666). Multivariable logistic regression analysis revealed the following independent factors influencing the detection of flat adenomas: patient-related factors of age, presence of warning symptoms, history of adenomas and bowel preparation as well as endoscopist-related factors of endoscopist's level of proficiency, number of colonoscopy operators and withdrawal time. CONCLUSIONS: The prevalence of flat adenomas in our study on Chinese patients was consistent with that reported from other countries. Factors conducive to the detection of flat adenomas were patient age of > 60 years, warning symptoms, history of adenoma, good bowel preparation, experienced endoscopist, single-operator colonoscopy and colonoscopy withdrawal time of >6 min.

Fe-based double perovskite with Zn doping for enhanced electrochemical performance as intermediate-temperature solid oxide fuel cell cathode material.

This study aims to investigate the implications of transition-metal Zn doping at the B-site on the crystal structure, average thermal expansion coefficient (TEC), electrocatalytic activity, and electrochemical performance of LaBaFe2O5+δ by preparing LaBaFe2-xZnxO5+δ (x = 0, 0.05, 0.1, 0.15, 0.2, LBFZx). The X-ray diffraction (XRD) results show that Zn2+ doping does not change the crystal structure, the unit cell volume increases, and the lattice expands. The X-ray photoelectron spectroscopy (XPS) and mineral titration results show that the oxygen vacancy concentration and Fe4+ content gradually increase with the increase in doping amount. TEC decreases with the increase in Zn2+ doping amount, and the TEC of LBFZ0.2 is 11.4 × 10-6 K-1 at 30-750 °C. The conductivity has the best value of 103 S cm-1 at the doping amount of x = 0.1. The scanning electron microscopy (SEM) images demonstrate that the electrolyte CGO(Gd0.1Ce0.9O1.95) becomes denser after high-temperature calcination, and the cathode material is well attached to the electrolyte. The electrochemical impedance analysis shows that Zn2+ doping at the B-site can reduce the (Rp) polarization resistance, and the Rp value of the symmetric cell with LaBaFe1.8Zn0.2O5+δ as cathode at 800 °C is 0.014 Ω cm2. The peak power density (PPD) value of the anode-supported single cell is 453 mW cm-2, which shows excellent electrochemical performance.

[Cathodoluminescent properties of Na2GdPO4F2:Tb3+ green phosphors].

The green emitting phosphors, Na2GdPO4F2:Tb3+, was synthesized by high temperature solid-state method. X-ray diffraction (XRD) and cathodoluminescence (CL) spectrum were used to characterize the samples. Under the low-voltage electron beam (0.5 - 5 kV) excitation, the Tb3+-doped Na2GdPO4F2 phosphor showed a very strong green emission corresponding to the characteristic transitions of Tb3+ (5D3,4 --> F(J) transitions, J = 6 - 2) with the strongest emission at 546 nm, corresponding to 5D4 --> F5 of Tb3+. The cathodoluminescent color of Na2Gd0.95Tb0.05PO4F2 was green to the naked eye with the Commission International de l'Eclairage (CIE) coordinates of x = 0.2403, y = 0.4386, and the color temperature at about 8634.3 K. The CL intensity increases upon raising the accelerating voltage, filament current and the doping concentrations, thereinto, the optimal concentrations of Tb3+ is 10 mol%.

[A new method for agreement evaluation based on AC1].

OBJECTIVE: Medical studies use various methods for assessing agreement among different raters or measurement methods. Many of these coefficients have limitations, and among them the paradoxes of kappa are the best known. To achieve a higher accuracy and reliability, we propose an alternative statistic method based on AC1, known as CEA, which adjusts the chance agreement. We explored the influences of the prevalence rate and chance agreement probability on the total agreement and compared the accuracy and stability of kappa, AC1 and CEA coefficient through simulations and real data analysis. The proposed method offers a stable and reliable option for assessing agreement of binary data.

[Expectant therapy versus curettage for retained products of conception after second trimester termination of pregnancy: analysis of outcomes and complications].

OBJECTIVE: To evaluate the prognosis and complications of expectant therapy and curettage for retained product of conception (RPOC) after second trimester termination of pregnancy (TOP). METHODS: A total of 270 patients with RPOC following second trimester TOP in Nanfang Hospital between January, 2014 and December, 2015 were included in this study. The duration of vaginal bleeding time and menstruation recovery interval were compared between patients receiving expectant therapy and curettage for RPOC, and binary logistic regression was used to assess the risk factors for complications in bivariate and multivariate analyses. RESULTS: The duration of vaginal bleeding time was significantly longer in expectant therapy group than in curettage group (P=0.005), while the menstruation recovery interval did not differ significantly between the two groups. The incidence of vaginal bleeding time for over 42 days was significantly higher in curettage group than in expectant therapy group (P=0.040), and the incidence of a menstruation recovery interval beyond 60 days was comparable between them. The incidence of complications was significantly higher in curettage group than in expectant therapy group either with adjustment of age, gravidity, parity, history of uterine surgery status, gestational age, type of indications, regimens for TOP and induction-abortion interval (OR=18.26 [95% CI: 3.57-93.42], P<0.001) or without adjustment (OR=10.60, [95% CI: 2.36-47.66], P=0.002). CONCLUSION: Expectant therapy and curettage for RPOC after second trimester TOP have comparable prognosis, but curettage is associated with a significantly higher rate of complications.

[Clinical efficacy and safety of controlled-release dinoprostone insert: a multicenter retrospective study].

OBJECTIVE: To analyze the effectiveness and safety of controlled-release dinoprostone insert for term labor induction in the Pearl River Delta of Guangdong province. METHODS: Twenty hospitals using controlled-release dinoprostone insert for term labor induction in the Pearl River Delta of Guangdong province were stratified into provincial hospitals and municipal hospitals, and three hospitals of each level were selected as research units. According to the inclusion and exclusion criteria, 1390 pregnant women receiving term labor induction using controlled-release dinoprostone insert were retrospectively analyzed to evaluate the the effectiveness and safety with another 957 pregnant women with induced abortion using oxytocin as the control group. RESULTS: Compared with the control group, the controlled-release dinoprostone insert group showed a significantly longer length of the latent phase of labor (4.06∓2.65 vs 3.20∓2.08 h, P=0.003, 95%CI [0.182, 0.920]) and shorter lengths of the active phase (1.73∓1.32 vs 2.22∓1.75 h, P=0.000, 95%CI [-0.795, -0.363]) and the second stage of labor (0.49∓0.37 vs 0.54∓0.43 h, P=0.003, 95%CI [-0.137, -0.028]). No significant differences were found in the length of the first stage of labor, the vaginal delivery rate, adverse reactions, or fetal outcomes between the two groups. CONCLUSION: Controlled-release dinoprostone insert is effective and safe for labor induction at term.

[Bibliometric analysis of the features of Journal of First Military Medical University in 21-24 volumes].

OBJECTIVE: To conduct a bibliometric evaluation of Journal of First Military Medical University. METHODS: With bibliometric method, a survey was carried out to analyze the articles, authors, rate of collaboration, publication type of citation, and publication stagnation in 21st-24th volumes. RESULTS: There were totally 1218 treatises in the 1860 articles published in the 4 volumes. Most of the authors were from institutes with good research strength, and 44 of them were core authors with at least 4 previous publications. The rate of collaboration in publication was 51.7% and 53.4% of the papers identified grants from various foundations or institutes. The average number of citation in a treatise was 9.93 and the publication stagnation averaged 196.1 days. CONCLUSION: The articles in this journal possess originality and are timely published. The authors show good ability for necessary information processing and contribute in various degrees to the development of the disciplines in medicine.

[Temperature changes of patients with severe acute respiratory syndrome: a comparative study].

OBJECTIVE: To explore the patterns of temperature changes of patients with the severe acute respiratory syndrome (SARS) and the effect of glucocorticoid hormone on the temperature of these patients. METHODS: The clinical data of 94 SARS cases treated during the outbreak of SARS in South China in 2003 were collected for a retrospective review. According to different treatment regimens, the patients were divided into hormone group (n=35) and non-hormone group (n=59). The control groups consisted of 65 patients with interstitial pneumonia, 78 with bacterial pneumonia and 57 with upper respiratory tract infection. The changes in body temperature were compared between the SARS patients and those with other respiratory diseases and the effect of glucocorticoid hormone on controlling body temperature of the SARS patients was explored. RESULTS: The body temperature of patients with the 4 diseases all exhibited obvious reduction 7 days after hospitalization (P<0.001) with only subsequent mild fluctuation within the basically normal range. At each time point of measurement, the body temperature of SARS patients was significantly higher than that of patients with other diseases (P<0.03), with a fluctuation of 0.2 to 0.5 degrees C; and following a pattern of variation similar to those of the other diseases. Of the 4 time points of daily measurement, namely 6, 10, 14 and 18 o'clock, the temperature measured at 14 o'clock was significantly higher than those at the other 3 time points (P<0.001). Hormone therapy did not significantly affect the temperature of SARS patients (P=0.180), who had longer duration of high fever. CONCLUSION: SARS patients have higher body temperature and longer duration of high fever. Hormone therapy may not produce significant effect in controlling the temperature of SARS patients.

Low Discrepancy Between Tissue Biopsy Plus Magnifying Endoscopy With Narrow-Band Imaging and Endoscopic Resection in the Diagnosis of Gastric Epithelial Neoplasia (STROBE).

Tissue biopsy is often not very accurate for the diagnosis of gastric epithelial neoplasia (GEN), and the results differ notably from endoscopic resection (ER) in terms of the pathological diagnosis. The aims of this study were to evaluate the diagnostic performances of biopsy, magnifying endoscopy with narrow-band imaging (ME-NBI), and biopsy plus ME-NBI for GEN.This study retrospectively analyzed 101 cases diagnosed as GEN using ER samples. The discrepancies between biopsy and ER, as well as between biopsy plus ME-NBI and ER in the diagnosis of GEN were evaluated. Factors that contributed to such discrepancies were analyzed. The sensitivity and specificity of biopsy and ME-NBI for the diagnosis of high-grade neoplasia (HGN) were determined.The discrepancy in the pathological diagnosis between biopsy and ER was 39.6% for GEN and 54.2% for HGN. The discrepancy between biopsy combined with ME-NBI and ER was 15.9% for GEN and 10.2% for HGN. Factors that undermined the diagnostic accuracy of biopsy included the lesion size (≤10 mm, odds ratio [OR] 1; 10-20 mm, OR 0.2, 95% confidence interval [CI] 0.1-0.7; >20 mm, OR 0.5, 95% CI 0.1-2.1, P = 0.03) and the number of biopsy fragments (OR 0.6, 95% CI 0.5-0.8, P = 0.001). The sensitivity and specificity for HGN were 45.8% (33.7%-58.3%) and 100% (87.5%-100%) for biopsy, and 88.1% (77.5%-94.1%) and 92.9% (81.0%-97.5%) for ME-NBI, respectively.In conclusion, biopsy-based diagnoses for GEN should be interpreted with caution. Biopsy combined with ME-NBI can contribute to the diagnosis of GEN, which improves diagnostic consistency with pathological result of ER specimens.

Myofibrotic malformation vessels: unique angiodysplasia toward the progression of hemorrhoidal disease.

BACKGROUND: The etiology and pathogenesis of hemorrhoids is unclear, although hemorrhoids are a worldwide disease in men and women, with peak prevalence at 45-65 years of age. Hemorrhoidal cushions as the anal venous plexi are normal anatomical structures from infancy. This study attempts to reveal the angiodysplasia and other pathological changes in association with different degrees of symptomatic hemorrhoids. MATERIALS AND METHODS: A total of 281 patients with internal hemorrhoids from degree I to IV underwent hemorrhoidectomy. The vascular changes were analyzed by microscopic assessment and software analysis, with Masson's trichrome, CD34, and smooth muscle actin. RESULTS: The hemorrhoidal tissues exhibited abnormal vessels in the mucosae and submucosae that we termed them as myofibrotic malformation vessels (MMVs). MMVs are not ascribed to arteries or veins because they exhibit enlarged and tortuous lumens with smooth muscle dysplasia and fibrotic deposition in the walls without overlying mucosal ulceration. The muscularis mucosae also showed smooth muscle dysplasia and fibrosis, even if it were interrupted by the intruding MMVs. The statistical data indicated that the severity of all the changes correlate positively with the progression of hemorrhoids (P<0.001). Hemorrhoidal patients are prone for reoccurrence even with prolapsing hemorrhoid when compared with the conventional hemorrhoidectomy. Multiple logistic regression analysis showed that MMVs in mucosal propria, mean thickness of mucosal muscularis layer, and fibrotic changes in MMV were independent risk factors for MMVs in hemorrhoidal disease. CONCLUSION: MMVs and muscularis mucosae dysplasia reciprocally contribute to hemorrhoidal exacerbation. The novel findings of this study propose that the characteristic features of MMVs and muscularis mucosae dysplasia of the anorectal tube ultimately cause symptomatic hemorrhoids, which could affect the clinical management of hemorrhoidal disease through the use of surgery to target the malformed vessels.

Training in early gastric cancer diagnosis improves the detection rate of early gastric cancer: an observational study in China.

Few studies have analyzed the training of endoscopists in the diagnosis of early gastric cancer (EGC). This study assessed whether specific training of endoscopists improves the detection rate of EGC. The rates of detection of EGC by endoscopists at the Digestive Endoscopy Center of the Affiliated Nanfang Hospital of China Southern Medical University between January 2013 and May 2014 were retrospectively analyzed. Because some endoscopists received training in the diagnosis of EGC, beginning in September 2013, the study was divided into 3 time periods: January to September 2013 (period 1), September 2013 to January 2014 (period 2), and January to May 2014 (period 3). The rates of EGC detection during these 3 periods were analyzed. From January 2013 to May 2014, a total of 25,314 gastroscopy examinations were performed at our center, with 48 of these examinations (0.2%) detecting EGCs, accounting for 12.1% (48/396) of the total number of gastric cancers detected. The EGC detection rates by trained endoscopists during periods 1, 2, and 3 were 0.3%, 0.6%, and 1.5%, respectively, accounting for 22.0%, 39.0%, and 60.0%, respectively, of the gastric cancers detected during these time periods. In comparison, the EGC detection rates by untrained endoscopists during periods 1, 2, and 3 were 0.05%, 0.08%, and 0.10%, respectively, accounting for 3.1%, 6.0%, and 5.7%, respectively, of the gastric cancers detected during these times. After training, the detection rate by some trained endoscopists markedly increased from 0.2% during period 1 to 2.3% during period 3. Further, the use of magnifying endoscopy with narrow-band imaging (M-NBI) (odds ratio = 3.1, 95% confidence interval 2.4-4.1, P < 0.001) contributed to the diagnosis of EGC. In conclusion, specific training could improve the endoscopic detection rate of EGC. M-NBI contributed to the diagnosis of EGC.

[Effect of Tribulus terrestris L decoction of different concentrations on tyrosinase activity and the proliferation of melanocytes].

OBJECTIVE: To study the effects of the decoction of Tribulus terrestris L on tyrosinase activity and melanogenesis. METHODS: MTT was employed to study the proliferation of human melanocytes cultured in vitro, and tyrosinase activity was estimated by measuring the rate of oxidation of DL-dopa, after the cells were treated with different concentrations of decoction of Tribulus terrestris L. RESULTS: The treatment with the decoction increased the amount of melanin at higher concentrations but act to the reverse effect at lower concentrations, with the best concentrations for promoting and inhibiting the cell growth being 1.5 mg/ml (P<0.05) and 0.5 mg/ml (P<0.05) respectively. At high concentrations the decoction enhanced the tyrosinase activity that was inhibited at low concentrations. The best concentrations for enhancing and inhibiting tyrosinase activity were 100 mg/ml (P<0.05) and 10 mg/ml (P<0.05) respectively. CONCLUSION: Tribulus terrestris L decoction exercises a two-way regulation on the activity of tyrosinase and the proliferation of melanocytes.

[Equivalence test and its performance with computer software].

Following brief introduction of the equivalence test, a sample is given to exemplify its performance with EquivTestTM 2.0 software and with the major results were interpreted.

[Probit analysis with SPSS 10.0 software].

The Probit analysis is illustrated with an example using Probit procedure of SPSS10.0 software, with interpretation of the major outputs.

[Clinical and pathological investigation of polymyositis and dermatomyositis: report of 83 cases].

OBJECTIVE: To study the clinical and pathological characteristics and treatment of polymyositis (PM) and dermatomyositis (DM). METHODS: Eighty-three DM/PM cases were reviewed and analyzed. RESULTS: The main clinical presentations of PM/DM included amyosthenia, muscular tenderness, elevation of serum enzymes, accompanied by abnormal electromyography and muscular pathology. A total efficacy rate of 86.7% was achieved after treatment with corticosteroid and immuno- depressants. CONCLUSION: The different clinical and pathological presentations of various types of PM/DM suggest different pathogenesis between DM and PM. Nerve damage is a part of the systemic damages due to the disease, the prognosis of which is related to its classification and then timing of the treatment. Early effective treatment can improve the prognosis.

Assessment of risk factors for delayed colonic post-polypectomy hemorrhage: a study of 15553 polypectomies from 2005 to 2013.

BACKGROUND AND AIM: Delayed colonic postpolypectomy bleeding is the commonest serious complication after polypectomy. This study aimed to utilize massive sampling data of polypectomy to analyze risk factors for delayed postpolypectomy bleeding. PATIENTS AND METHODS: The endoscopic data of 5600 patients with 15553 polyps removed (2005 to 2013) were analyzed retrospectively through univariate analysis and multiple logistic regression analysis to evaluate the risk factors for delayed bleeding. RESULTS: Delayed postpolypectomy bleeding occurred in 99 polyps (0.6%). The rates of bleeding for different polypectomy methods including hot biopsy forcep, biopsy forcep, Argon Plasma Coagulation (APC), Endoscopy piecemeal mucosal resection (EPMR), Endoscopic Mucosal Resection (EMR), and snare polypectomy were 0.1%, 0.0%, 0.0%, 6.9%, 0.9% and 1.0%, respectively. The risk factors for delayed bleeding were the size of polyps over 10 mm (odds ratio [OR] = 4.6, 95% CI, 2.9-7.2), pathology of colonic polyps (inflammatory/hyperplastic, OR = 1; adenomatous, OR = 1.4, 95% CI, 0.7-2.6; serrated, OR = 1.5, 95% CI, 0.2-11.9; juvenile, OR = 4.3, 95% CI, 1.8-11.0; Peutz-Jegher, OR = 3.3, 95% CI, 1.0-10.7), and immediate postpolypectomy bleeding (OR = 2.9, 95% CI, 1.4-5.9). In addition, although polypectomy method was not a risk factor, compared with hot biopsy forcep, snare polypectomy, EMR, and EPMR had increased risks of delayed bleeding, with ORs of 3.2 (0.4-23.3), 2.8 (0.4-21.7) and 5.1 (0.5-47.7), respectively. CONCLUSION: Polyp size over 10 mm, pathology of colonic polyps (especially juvenile, Peutz-Jegher), and immediate postpolypectomy bleeding were significant risk factors for delayed postpolypectomy bleeding.

Risk factors associated with missed colorectal flat adenoma: a multicenter retrospective tandem colonoscopy study.

AIM: To determine the miss rate for colorectal flat adenomas during colonoscopy and the risk factors. METHODS: Flat adenomas are frequently missed during colonoscopy. However, the risk factors that influence their miss rates are unclear. This was a multicenter, retrospective study in which patients diagnosed with colorectal adenomas at a diagnostic colonoscopy and followed within 3 mo by a second therapeutic colonoscopy were pooled out from the established database. The "per-patient" and "per-adenoma" adenoma miss rates (AMR) for overall adenomas and flat adenomas, and patient-, adenoma-, and procedure-related risk factors potentially associated with the "per-adenoma" AMR for flat adenomas were determined. RESULTS: Chromoscopy and high-definition colonoscopy were not taken under consideration in the study. Among 2093 patients with colorectal adenomas, 691 (33.0%) were diagnosed with flat adenomas, 514 with concomitant protruding adenomas and 177 without. The "per-patient" AMR for flat adenomas was 43.3% (299/691); the rates were 54.3% and 11.3%, respectively, for those with protruding adenomas and those without (OR = 9.320, 95%CI: 5.672-15.314, χ (2) = 99.084, P < 0.001). The "per-adenoma" AMR for flat adenomas was 44.3% (406/916). In multivariate analysis, older age, presence of concomitant protruding adenomas, poor bowel preparation, smaller adenoma size, location at the right colon, insufficient experience of the colonoscopist, and withdrawal time < 6 min were associated with an increased "per-adenoma" AMR for flat adenomas. The AMR for flat adenomas was moderately correlated with that for overall adenomas (r = 0.516, P < 0.0001). The AMR for flat adenomas during colonoscopy was high. CONCLUSION: Patient's age, concomitant protruding adenomas, bowel preparation, size and location of adenomas, proficiency of the colonoscopist, and withdrawal time are factors affecting the "per-adenoma" AMR for flat adenomas.