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Influence of main site factors on Fraxinus mandshurica (Oleaceae) plantation 被引量:5
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作者 苏含英 林代斌 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第1期83-86,共4页
the investigation was carried out on 10-year-old plantation of Fraxinus mandshurica in Mao抏r Mountain Experimental Station of Northeast Forest University. Tree height (H), diameter at breast height (D1.3) and the inc... the investigation was carried out on 10-year-old plantation of Fraxinus mandshurica in Mao抏r Mountain Experimental Station of Northeast Forest University. Tree height (H), diameter at breast height (D1.3) and the increment of tree height in 5 years (H5), the thickness of humus layer, as well as the soil moisture were measured for the plantation and the growth indexes (H, D1.3, H5) for different site conditions were analyzed. The results showed that main site factors influencing the growth of Fraxinus mandshurica were soil moisture, gradient and location of slope in order. The growth of Fraxinus mandshurica was better on the middle- or up-slope site than on the down-slope site. Soil moisture and late frost caused by terrain are the main reasons that limit the growth of Fraxinus mandshurica plantation. 展开更多
关键词 Fraxinus mandshurica PLANTATION site factors
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QUANTITATIVE ANALYSIS OF RELATIONSHIP BETWEEN ARMILLARIA ROOT ROT AND SITE FACTORS IN PINUS RADIATA PLANTATIONS
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作者 Shu Qinglong He Min +1 位作者 Song Shumei Zhao Weizhong(Department of Forestry,Anhui Agricultural University,Hefei 230036)(School of Forestry,University of Canterbury,Christchurch,New Zealand)(Shanxi Agricultura1 University,Taigu,shanxi.) 《生物数学学报》 CSCD 北大核心 1995年第3期9-14,共6页
Incidence of Armillaria infection was quantified based on site factors in New Zealand Pinus radiata plantations.A linear multiple regression model was derived to predict infection levels of Armillaria root rot.Factors... Incidence of Armillaria infection was quantified based on site factors in New Zealand Pinus radiata plantations.A linear multiple regression model was derived to predict infection levels of Armillaria root rot.Factors positivily associated with the infection were:previous vegetation(native bush,pine);soil type(pumice);landform (valley,gully,flat)and the interaction between them.This model could assist in management planning with regard to the predisposition of particular stand to Armillaria infection.Keywods:Armillaria root rot,Disease incidence,Site factors,Quantification,Pinus radiata. 展开更多
关键词 site ROOT ROOT QUANTITATIVE ANALYSIS OF RELATIONSHIP BETWEEN ARMILLARIA ROOT ROT AND site factorS IN PINUS RADIATA PLANTATIONS
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RELATIONSHIPS BETWEEN LARCH GROWTH AND FOREST SITE FACTORS
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作者 Wang Zhcngquan (1) Wang Fenguou (1) Gong Weiguang (1) 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1990年第1期42-54,共13页
Dahurian larch (Larix gmelinii Rupr.) Rupr is one of the dominant species in bothnatural and man-made forests in northeast China.Effects of site factors,including topography,soilproperties and nutrient elements(P,Ca,K... Dahurian larch (Larix gmelinii Rupr.) Rupr is one of the dominant species in bothnatural and man-made forests in northeast China.Effects of site factors,including topography,soilproperties and nutrient elements(P,Ca,K,Mg,Mn,Zn,Cu,Ag,Co and Ni)on the growth of larchwere analyzed in detail,qualitatively and quantitatively.The ordination technique was used to groupthe site factors and to classify sites for larch.Analysis indicated that height growth,diameter(DBH)and volume of the larch varied among site types and this will be of theoretical and practical signifi-canee in developing larch plantations. 展开更多
关键词 LARIX gmelinii. FOREST site site factors NORTHEAST China
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Prevalence and Risk Factors for Surgical Site Infection Following Cesarean Section in a Tertiary Care Hospital
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作者 Nafisa Ahamed Md. Alimur Reza +3 位作者 Kakali Saha Rabeya Khanom Shovana Talukder Arifa Akram 《Open Journal of Obstetrics and Gynecology》 2025年第2期261-271,共11页
Background: Cesarean sections have become increasingly prevalent in both developed and developing nations. Nevertheless, postoperative complications, including surgical site infections (SSIs), remain a substantial con... Background: Cesarean sections have become increasingly prevalent in both developed and developing nations. Nevertheless, postoperative complications, including surgical site infections (SSIs), remain a substantial concern that contributes to heightened morbidity and mortality. This study is designed to evaluate the frequency and key determining factors associated with surgical site infections following cesarean section procedures in a tertiary care hospital in Bangladesh. Materials and Methods: This observational cross-sectional study, conducted at the Gynecology Department of Dhaka Medical College Hospital, involved 100 patients aged 15 - 45 who had cesarean deliveries. Data was collected during hospitalization and post-discharge and analyzed to determine the prevalence and relationship between socio-demographic characteristics and surgical site infection. Results: Among the study participants, 14% developed surgical site infections following cesarean operations. More than half of these patients were under the age of 25, with a mean age of 24.45 ± 4.44 years. Surgical site infections were more prevalent in individuals over 30 years old (P-value Conclusion: Post-cesarean surgical site infections are notably prevalent among the participants in this study. Several risk factors have been identified, including age, body mass index (BMI), socioeconomic status, anemia, preterm delivery, personal hygiene practices, regular menstrual cycles, and adherence to antenatal check-ups. The implementation of an effective awareness program, coupled with updated antibiotic protocols, is crucial for significantly reducing the incidence of these infections. 展开更多
关键词 Surgical site Infection (SSI) Cesarean Section Risk factors
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Incidences and Risk Factors for Surgical Site Infections in Koutiala, Mali
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作者 Mahamadou Coulibaly Moussa Diassana +9 位作者 Issiaka Diarra Bréhima Bengaly Birama Togola Drissa Ouattara Souleymane Sanogo Samuel Kletigui Dembélé Cheick Aka Waigalo Brehima Ballo Drissa Traoré Nouhoum Ongoiba 《Surgical Science》 2024年第7期465-469,共5页
Purpose: This paper aims to assess the incidences and risk factors for surgical site (ISO) infections in the general surgery department of the Koutiala District Hospital. Patients and Methods: This was a prospective a... Purpose: This paper aims to assess the incidences and risk factors for surgical site (ISO) infections in the general surgery department of the Koutiala District Hospital. Patients and Methods: This was a prospective and descriptive study from August 1, 2017 to October 31, 2020 involving all patients who underwent laparotomy in the general surgery department of the Koutiala District Hospital. Patients who were not operated on and who did not have a laparotomy were not included. Age, sex, frequency, patient history, National Nosocomial Infections Surveillance (NNIS) index, time to occur, bacteriological test results and course of infection were analyzed. Results: Fifty patients were registered. The average age was 34.2 ± 21.2 years old. Eleven patients were 60 years old or older. The hospital incidence rate was 4.3% and the community incidence rate was 6.1 cases per 100,000 population. The concept of smoking was noted in 15 patients. Patients were operated on in emergency 84% of cases. Peritonitis was the most common initial lesion with 32% of cases. Our patients had an NNIS index greater than 0 in 84% of cases. The time to develop infection from the surgical site was less than 3 days in 8 patients (16% of cases). Depending on the depth of the infection, it was superficial (cutaneous) in 39 patients (78%) and deep (subcutaneous and organic) in 11 patients (22%). Escherichia coli was the most common germ with 72% followed by staphylococcus aureus at 24%. We noted 22% morbidity. The median length of hospitalization was 9 ± 2.2 days. Conclusion: ISO is common in our service. Prevention and mastery require knowledge of risk factors. 展开更多
关键词 Surgical site Infection INCIDENCE Risk factors SURGERY
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Improving kinetic modelling of magnesium hydrogenation by including interfacial polarisation and interstitial hydrogen clustering behaviour within the site availability model
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作者 Marcus J.Adams Alastair Stuart +1 位作者 Gavin S.Walker David M.Grant 《Journal of Magnesium and Alloys》 2025年第5期2009-2022,共14页
Recent work analysing magnesium hydrogenation using Reflecting Electron Energy Loss Spectroscopy(REELS)and Density Function Theory(DFT)has indicated interfacial polarisation and interstitial hydrogen clustering influe... Recent work analysing magnesium hydrogenation using Reflecting Electron Energy Loss Spectroscopy(REELS)and Density Function Theory(DFT)has indicated interfacial polarisation and interstitial hydrogen clustering influence the reaction rate.The site availability model has been modified to include interstitial hydrogen clustering within the site availability factor and interface polarisation using interface treatment.The new model,SAM-CV-S,has demonstrated improved modelling of magnesium hydrogenation across wide operating conditions,such as temperatures from 330 to 400℃and pressures up to 40 bar.This wide applicability makes it a robust model that can be used to simulate bed performance in solid-state hydrogen stores.Thus,the site availability factor successfully combines interstitial hydrogen clustering with thermal resistance effects,which are known to strongly influence metal hydride reactor designs at scale.The next phase of the model is to incorporate a predictive hydrogen capacity method into the model. 展开更多
关键词 Magnesium hydrogenation kinetics site availability factor Interstitial hydrogen clustering Interfacial polarisation
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Systematic identification and annotation of multiple-variant compound effects at transcription factor binding sites in human genome 被引量:1
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作者 Si-Jin Cheng Shuai Jiang +2 位作者 Fang-Yuan Shi Yang Ding Ge Gao 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2018年第7期373-379,共7页
Understanding the functional effects of genetic variants is crucial in modern genomics and genetics. Transcription factor binding sites (TFBSs) are one of the most important cis-regulatory elements. While multiple t... Understanding the functional effects of genetic variants is crucial in modern genomics and genetics. Transcription factor binding sites (TFBSs) are one of the most important cis-regulatory elements. While multiple tools have been developed to assess functional effects of genetic variants at TFBSs, they usually assume that each variant works in isolation and neglect the potential "interference" among multiple variants within the same TFBS. In this study, we presented COPE-TFBS (Context-Oriented Predictor for variant Effect on Transcription Factor Binding Site), a novel method that considers sequence context to accurately predict variant effects on TFBSs. We systematically re-analyzed the sequencing data from both the 1000 Genomes Project and the Genotype-Tissue Expression (GTEx) Project via COPE-TFBS, and identified numbers of novel TFBSs, transformed TFBSs and discordantly annotated TFBSs resulting from multiple variants, further highlighting the necessity of sequence context in accurately annotating genetic variants. 展开更多
关键词 Compound effect Transcription factor binding site Variant annotation BIOINFORMATICS Genetic variants
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Studying the depth-dependent variation of site magnification factor in Dongchuan by earthquakes observed in borehole
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作者 罗娣华 蒋乐群 +3 位作者 陈敏恭 叶建庆 蔡少平 刘学军 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2001年第1期72-81,118,共11页
The digital seismometers with high accuracy are installed at depths of -200 m, -100 m in borehole and on the surface in Dongchuan. By analysis of spectra ratio, the local events (with epicentral distances between 8.5 ... The digital seismometers with high accuracy are installed at depths of -200 m, -100 m in borehole and on the surface in Dongchuan. By analysis of spectra ratio, the local events (with epicentral distances between 8.5 km and 95 km, magnitudes ML = 1.3-5.1) recorded are used to calculate site magnification factor at different depths (-100 m and surface) in Dongchuan. Comparing results with that at the depth of -200 m, the site magnification factors at three components of N-S, E-W and U-D corresponding to the depth of -100 m at 8 frequencies (f = 0.75, 1.0, 1.5, 2, 3, 4, 6, and 12 Hz) are 1.0-1.49 when 0.75 Hz- [less-than or equal to] f [less-than or equal to] 2 Hz and 0.47-0.99 when 2 Hz less than or equal f less than or equal 12 Hz. On the surface, site magnification factors at three components are all greater than 1, i.e. between 1.6 and 7.63. The correlation coefficients of site magnification factors for S wave and coda at the depth of -100 m and on surface are 0.82 and 0.81 when 0.75 Hz [less-than or equal to] f [less-than or equal to] 2 Hz, 0.47 and 0.45 when 2 Hz less than or equal f less than or equal 12 Hz, respectively. 展开更多
关键词 S wave CODA noise site magnification factor
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Identifying changes in punitive transcriptional factor binding sites from regulatory single nucleotide polymorphisms that are significantly associated with disease or sickness 被引量:1
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作者 Norman E Buroker 《World Journal of Hematology》 2016年第4期75-87,共13页
AIM To identify punitive transcriptional factor binding sites(TFBS) from regulatory single nucleotide polymorphisms(rS NPs) that are significantly associated with disease.METHODS The genome-wide association studies ha... AIM To identify punitive transcriptional factor binding sites(TFBS) from regulatory single nucleotide polymorphisms(rS NPs) that are significantly associated with disease.METHODS The genome-wide association studies have provided us with nearly 6500 disease or trait-predisposing SNPs where 93% are located within non-coding regions such as gene regulatory or intergenic areas of the genome. In the regulatory region of a gene, a SNP can change the DNA sequence of a transcriptional factor(TF) motif and in turn may affect the process of gene regulation. SNP changes that affect gene expression and impact gene regulatory sequences such as promoters, enhancers, and silencers are known as rS NPs. Computational tools can be used to identify unique punitive TFBS created by rS NPs that are associated with disease or sickness. Computational analysis was used to identify punitive TFBS generated by the alleles of these rS NPs.RESULTS r SNPs within nine genes that have been significantly associated with disease or sickness were used to illustrate the tremendous diversity of punitive unique TFBS that can be generated by their alleles. The genes studied are the adrenergic, beta, receptor kinase 1, the v-akt murine thymoma viral oncogene homolog 3, the activating transcription factor 3, the type 2 demodkinase gene, the endothetal Per-Arnt-Sim domain protein 1, the lysosomal acid lipase A, the signal Transducer and Activator of Transcription 4, the thromboxane A2 receptor and the vascular endothelial growth factor A. From this sampling of SNPs among the nine genes, there are 73 potential unique TFBS generated by the common alleles comparedto 124 generated by the minor alleles indicating the tremendous diversity of potential TFs that are capable of regulating these genes.CONCLUSION From the diversity of unique punitive binding sites for TFs, it was found that some TFs play a role in the disease or sickness being studied. 展开更多
关键词 REGULATORY single nucleotide polymorphisms Alleles TRANSCRIPTIONAL factors TRANSCRIPTIONAL factor binding sites Linkage disequilibrium DISEASE or SICKNESS
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Surgical Site Infection (SSI) in the National Referral General Hospital of Ndjamena (Chad): Survey about Risk Factors
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作者 Hassan Mahamat Ali Yeri Esther Hien +7 位作者 Cheikna Zongo Denis Erbi Ali Haroun Hissein François Tapsoba Abacar Mahamat Tahir Brahim Adoum Ahamt Yves Traore Aly Savadogo 《Journal of Biosciences and Medicines》 2021年第5期1-11,共11页
The risk to develop an infection after surgery depends on several factors. Those factors may be interdependent or not, depending on the nature of the surgery and the general condition of the patient. The aim of the pr... The risk to develop an infection after surgery depends on several factors. Those factors may be interdependent or not, depending on the nature of the surgery and the general condition of the patient. The aim of the present study was to identify the factors involved in the occurrence of the Surgical Site Infections (SSI) in the <strong><em>National referral general hospital </em></strong>of N’djamena (Chad). We first realized an interview in the emergency services and in the general surgery of the hospital. The information collected allowed us to draw up survey sheets. An investigation was then conducted on 152 patients who had surgery and were hospitalized during the study period. The frequency of the SSI was 33.6% (51/152). The main risk factors that we identified were the duration of hospitalization, the category of the hospitalization room, the urgent aspect of the surgical intervention, the patient’s nutritional status and the associated diseases with diabetes, which was present in 52.38% (11/21) of cases of associated pathologies. Analysis of the antibiotic prophylaxis administered to patients showed that ciprofloxacin was more effective in SSI prevention. Indeed, this antibiotic showed the fewest cases of infection with only 1.9% of patients having developed SSI. Our results show a very high frequency of SSI at the <strong><em>National referral general hospital</em></strong> of N’djamena. Poor hospital practices and factors associated to patients seem to be the most factors implicated in the SSI. 展开更多
关键词 Surgical site Infections Risk factors Nutritional Status Associated Diseases CHAD
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The Measurement and Uncertainty Analysis of Antenna Factor of Microwave Antennas Based on Standard Site Method
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作者 Chaochan Chen Hong Shi +1 位作者 Yi Miao Yu Sang 《International Journal of Communications, Network and System Sciences》 2017年第5期138-145,共8页
A method of Standard Site Method (SSM) in the American National Standards Institute’s ANSI C63.5 is described in the frequency ranges from 30 MHz to 1000 MHz. And a measurement system is set up for determining antenn... A method of Standard Site Method (SSM) in the American National Standards Institute’s ANSI C63.5 is described in the frequency ranges from 30 MHz to 1000 MHz. And a measurement system is set up for determining antenna factors (AF) of antennas on an Open Area Test Sites (OATS). AF of antennas including log-periodic antenna and biconical antenna is measured with SSM method by Shanghai Institute of Measurement and Testing Technology (SIMT), which shows good agreement to data measured by National Institute of Metrology (NIM). In the end, it analyzes the measurement uncertainty of SIMT in the 30 MHz to 1000 MHz frequency band and does comparison to that of NIM. 展开更多
关键词 ANTENNA factorS Standard site Method (SSM) MEASUREMENT UNCERTAINTY
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A distribution pattern assisted method of transcription factor binding site discovery for both yeast and filamentous fungi
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作者 Jinnan Hu Chenxi Chen +1 位作者 Kun Huang Thomas K. Mitchell 《Advances in Bioscience and Biotechnology》 2013年第4期509-517,共9页
Transcription factors (TFs) are the core sentinels of gene regulation functioning by binding to highly specific DNA sequences to activate or repress the recruitment of RNA polymerase. The ability to identify transcrip... Transcription factors (TFs) are the core sentinels of gene regulation functioning by binding to highly specific DNA sequences to activate or repress the recruitment of RNA polymerase. The ability to identify transcription factor binding sites (TFBSs) is necessary to understand gene regulation and infer regulatory networks. Despite the fact that bioinformatics tools have been developed for years to improve computational identification of TFBSs, the accurate prediction still remains changeling as DNA motifs recognized by TFs are typically short and often lack obvious patterns. In this study we introduced a new attribute-motif distribution pattern (MDP) to assist in TFBS prediction. MDP was developed using a TF distribution pattern curve generated by analyzing 25 yeast TFs and 37 of their experimentally validated binding motifs, followed by calculating a scoring value to quantify the reliability of each motif prediction. Finally, MDP was tested using another set of 7 TFs with known binding sites to in silico validate the approach. The method was further tested in a non-yeast system using the filamentous fungus Magnaporthe oryzae transcription factor MoCRZ1. We demonstrate superior prediction reranking results using MDP over the commonly used program MEME and the other four predictors. The data showed significant improvements in the ranking of validated TFBS and provides a more sensitive statistics based approach for motif discovery. 展开更多
关键词 Transcription factor Binding site DISCOVER Distribution Pattern SACCHAROMYCES CEREVISIAE MAGNAPORTHE ORYZAE MoCRZ1
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A Study on the Influencing Factors on Ground Motion in a Valley Site
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作者 LI Ping BO Jingshan +1 位作者 XIAO Ruijie ZHANG Yudong 《Earthquake Research in China》 CSCD 2019年第1期62-73,共12页
A trapezoid valley site is chosen as a research site,and according to numerical models based on orthogonal design,the factors influencing ground motion in the valley site are studied with two-dimensional finite differ... A trapezoid valley site is chosen as a research site,and according to numerical models based on orthogonal design,the factors influencing ground motion in the valley site are studied with two-dimensional finite difference method. The influencing factors are ranked,and then the calculation results are verified by ground motion analysis. The conclusions are as follows:there are four factors that have important effects on ground motion of trapezoid valley sites,but the effects are different as the location of sites changes,the influencing factors rank differently with different site locations; The ranking of the influencing factors is the same for all the sites located within a distance of 40m from the valley's side,among them,the most effective one is the valley slope angle ranks,followed by depth-to-width ratio,overburden thickness,at last the input ground motion intensity.The impact of the factors on surface ground motion is roughly the same in the valley sites within a certain distance to the valley side,and the geometric parameters of the valley terrain play a greater part in influencing ground motion. With the increase of distance away from the valley's side,the ranking of the influencing factors also changes,the rating of slope angle moves backward,the ranking of the input ground motion and overburden thickness move ahead. The effect of valley geometric parameters on ground motions is gradually weakened,but the effect of other two influence factors are gradually increased,similar to cases of a horizontal layered site. Strong motion records in Anning River valley site were analyzed,and the results show that the valley topography has a significant amplification effect on ground motion,and that the numerical results of this paper are credible. 展开更多
关键词 VALLEY site Ground motion FINITE DIFFERENCE Influencing factorS
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Risk Factors for Surgical Site Infections in Patients Operated at the University Clinic of Traumatology-Orthopedics and Restorative Surgery of the National Hospital and University Center Hubert Koutoukou Maga in Cotonou
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作者 Comlan Cyriaque Dégbey Charles Patrick Makoutodé +1 位作者 Narjolès Augustino Houngnandan Badirou Aguemon 《Open Journal of Epidemiology》 2023年第1期1-15,共15页
Background: Operative site infections (ISO) are typically nosocomial. According to the WHO the incidence of ISO varies from 0.5% to 15% and exceeds 25% in developing countries. They result from the combined action of ... Background: Operative site infections (ISO) are typically nosocomial. According to the WHO the incidence of ISO varies from 0.5% to 15% and exceeds 25% in developing countries. They result from the combined action of several factors and represent a concern for public health. To study the contributing factors of surgical site infections in patients operated at the University Clinic of Orthopedic Traumatology of CNHU-HKM of Cotonou. Method: This was an analytical cross-sectional study that involved 35 operated patients and ten nurses. Were included in our study: 1) All patients, without distinction of sex or age, having been operated on in the university clinic of orthopedic traumatology, during the survey period;2) Patients hospitalized for post-operative care during the survey period;3) The nursing staff on duty during our study period. The usual statistical measures were used according to the type of variables: means, standard deviations, percentages. Data analysis first involved calculating percentages for the qualitative variables and means followed by their standard deviations for the quantitative variables. Next, the Pearson Chi-square test was used to test the association between the dependent variable and the independent variables of interest. The significance level is set at p Results: The prevalence of surgical site infections was 28.58%. The main factors contributing to the occurrence of SSIs that were found were the patient’s level of education (p = 0.003) and the reuse of bandages used for dressing (p = 0.004). Other potential factors such as the economic status of the patient, the poor quality of technical dressings, and the preoperative stay were also highlighted. Conclusion: Surgical site infections remain a global concern. Risk factors were found on both the patient and nurse sides. It is urgent to address these various factors to minimize the occurrence of surgical site infections. 展开更多
关键词 Surgical site Infection Nosocomial Infections Risk factors Patient BENIN
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Risk Factors for Surgical Site Infection after Hip Arthroplasty: A Multicentric Study
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作者 Gabriel B. Tofani Gustavo P. Irffi +4 位作者 Lucas F. Silva Cynthia C. M. da Silva Bráulio R. G. M. Couto Gilberto D. Miranda Carlos E. F. Starling 《Surgical Science》 2016年第2期58-64,共7页
The objective of this study is to answer three main questions: What is the risk of wound infection for patients undergoing hip arthroplasty? What are the main etiologicagents of surgical site infection (SSI)? What are... The objective of this study is to answer three main questions: What is the risk of wound infection for patients undergoing hip arthroplasty? What are the main etiologicagents of surgical site infection (SSI)? What are the risk factors most associated with surgical site infection? Method: This was a multicentric, retrospective cohort study which analyzed data collected in five general hospitals in Belo Horizonte, Brazil, between the period of January 2009 and December 2013. The continuous parameters studied were age, length of hospital stay before surgery, duration of surgery, number of professionals at surgery and number of hospital admissions. Categorical variables were surgical wound classification (clean, clean contaminated, contaminated, dirty/infected), American Society of Anesthesiologists (ASA) score (I, II, III, IV, V), type of surgery (elective, emergency), general anesthesia (yes, no), prophylactic antibiotic (yes, no), trauma surgery (yes, no) and Nosocomial Infections Surveillance (NNIS) risk index (IRIC = 0, 1, 2, 3). Results: Estimated SSI risk was 3.2% (95% C.I. = 2.6% to 4.1%) and risk of osteomyelitis was 0.6% (95% C.I. = 0.4% to 1.1%). ASA score > 2, general anesthesia, length of hospital stay before surgery higher than four days, more than two professionals at surgical field and duration of surgery higher than five hours were risk factors for SSI after hip prosthesis (p < 0.05). The final multiple logistic regression analysis indicated that the modified NNIS risk was independently associated with surgical site infection after arthroplasty of hip. Conclusion: Despite the modified NNIS index being a risk factor for SSI, none of its independent variables was statistically significantly in the logistic model (p > 0.100). Each modified NNIS risk category increased the chance of a patient being infected by almost three times, when compared with the previous category (OR = 2.82;p = 0.011). 展开更多
关键词 Surgical site Infection Hip Arthroplasty Hip Replacement Risk factors
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区划图中场地影响调整系数检验——以天津地区为例
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作者 任叶飞 张鹏 +2 位作者 赵宇 史丙新 温瑞智 《工程力学》 北大核心 2025年第10期223-232,共10页
中国第五代区划图给出的场地影响调整系数是否普适于全国所有地区,目前尚未开展有效检验。该文以天津地区的Ⅲ类、Ⅳ类场地为例,通过收集的137个工程钻孔资料和土动力学参数数据,建立一维等效线性化地震反应计算模型,基于NGA-West2数据... 中国第五代区划图给出的场地影响调整系数是否普适于全国所有地区,目前尚未开展有效检验。该文以天津地区的Ⅲ类、Ⅳ类场地为例,通过收集的137个工程钻孔资料和土动力学参数数据,建立一维等效线性化地震反应计算模型,基于NGA-West2数据库的144条基岩场地强震动记录,计算了这些场地的PGA放大系数K_(a)和反应谱特征周期T_(g),与区划图规定值和已有研究给出的推荐值进行了比较分析。得到如下结论:K_(a)的中值随输入PGA水平的增加而降低,与区划图的地震动峰值加速度调整系数Fa变化规律一致,体现了场地非线性反应的影响,并且在大震时该影响表现更为突出;K_(a)达到Fa值的累积概率在很多工况下都高于80%,表明五代区划图给出的PGA场地影响调整系数具有较高的保证率,也说明了规范具有一定的安全冗余度;五代区划图Fa值与该文计算结果和已有研究都较为接近,并且基本上不小于该文计算的K_(x)+S值,表明区划图给出的场地峰值加速度调整系数针对天津地区Ⅲ类、Ⅳ类场地是合理适用的;Ⅲ类场地T_(g)中位值高于区划图规定值,且与Ⅳ类场地计算值相近,表明区划图的场地影响调整系数须考虑我国场地条件的区域差异性。该研究可为区划图在其他地区的检验和下一代区划图的完善提供重要启示。 展开更多
关键词 地震区划图 场地类别 一维等效线性化场地地震反应 PGA放大系数 场地影响系数 特征周期
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Hazardous and Harmful Factors on Construction Sites and Their Prevention
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作者 ZHENG Huanqiang ZHANG Zaiwang RONG Kun 《Journal of Landscape Research》 2019年第1期20-23,28,共5页
In this paper, the status quo of safety production on construction sites and the hazardous and harmful factors in the construction process were analyzed, and corresponding suggestions were proposed to make up for the ... In this paper, the status quo of safety production on construction sites and the hazardous and harmful factors in the construction process were analyzed, and corresponding suggestions were proposed to make up for the shortcomings of the safety production assurance system standards on construction sites. 展开更多
关键词 CONSTRUCTION site Safety PRODUCTION MANAGEMENT Identification of hazardous and harmful factorS
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基于密集线性台阵地震被动源成像的渭河盆地西缘精细沉积结构研究
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作者 徐勇 邓宝 +4 位作者 田晓峰 倪红玉 段永红 肖本夫 李俊伦 《地质学报》 北大核心 2025年第5期1508-1522,共15页
为研究渭河盆地西缘强震风险重点区域的地下精细结构和沉积特征,本研究布设了一条由平均台站间距200 m、共254个短周期三分量节点式地震仪组成的密集线性台阵,进行了为期30天的连续地震数据采集。我们首先计算了背景噪声垂直分量的互相... 为研究渭河盆地西缘强震风险重点区域的地下精细结构和沉积特征,本研究布设了一条由平均台站间距200 m、共254个短周期三分量节点式地震仪组成的密集线性台阵,进行了为期30天的连续地震数据采集。我们首先计算了背景噪声垂直分量的互相关,应用近期发展的拓距相移法提取了3 Hz~3.3 s的基阶瑞利面波频散曲线,进而反演得到测线下方2.5 km以浅的高分辨率横波速度结构。此外,利用采集到的三分量背景噪声数据,采用单台噪声谱比法(HVSR)计算峰值频率,根据经验公式估计了渭河盆地沉积层厚度。背景噪声成像获得的二维横波速度剖面呈现出高速—低速—高速的横向变化特征,与典型沉积盆地隆起—坳陷—隆起的地质结构吻合,清晰刻画了区域内3条主控断裂和2个地质构造单元,与地震主动源反射剖面结果一致;HVSR成像结果揭示了研究区域内沉积层较厚,层序明显,新生界的古近系、新近系和第四系的地层层序发育完整;结合背景噪声成像、HVSR和已有主动源地震反射剖面等资料,综合研究表明测线下方存在的3条主控断裂在该区域均未穿透第四系。本研究表明背景噪声拓距相移法和HVSR方法结合在沉积盆地结构探测中具有良好的实际应用效果,为沉积盆地结构探测提供了新的技术方法和途径。 展开更多
关键词 渭河盆地 沉积结构 背景噪声成像 拓距相移法 场地放大效应
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紫椴研究进展
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作者 林士杰 王梓默 +4 位作者 朱红波 王聪慧 勾天兵 韩姣 何怀江 《中国农学通报》 2025年第31期7-13,共7页
为系统梳理紫椴研究脉络、深化对其资源特性的认知,并推动紫椴资源的科学保护与高效利用,本文从生理学、生态学、遗传改良和繁育技术4个核心领域,全面综述了近年来紫椴的研究进展。在生理学研究方面,分析了低温胁迫、盐胁迫、施肥管理... 为系统梳理紫椴研究脉络、深化对其资源特性的认知,并推动紫椴资源的科学保护与高效利用,本文从生理学、生态学、遗传改良和繁育技术4个核心领域,全面综述了近年来紫椴的研究进展。在生理学研究方面,分析了低温胁迫、盐胁迫、施肥管理及光照强度调控对紫椴叶片渗透调节物质、光合生理指标等关键生理特性的影响机制;在生态学研究方面,阐述了混交造林模式、立地因子(坡度、坡向、土壤厚度等)对紫椴生长动态的作用规律,以及间伐强度对紫椴林分木材材质(生长轮密度、力学强度等)的调控效应。遗传改良研究部分,归纳了紫椴种源筛选、种子园营建(含“加密式”定植、“双向逆行网眼式错位法”配置等关键技术)、优良家系与优良无性系筛选的最新成果;繁育技术研究部分,详细总结了紫椴种子繁殖(种子休眠解除方法、播种密度优化)、嫁接繁殖(最佳嫁接时间与方法筛选)、扦插繁殖(基质与激素组合优化)及组织培养(不同培养基配方与外植体选择)的技术参数与应用效果。最后,结合当前研究现状与生产需求,提出未来紫椴研究应聚焦4个方向:(1)加强紫椴种质资源的系统性收集、评价与长效保存;(2)研发紫椴营养器官(如腋芽、茎段)组培快繁技术体系并推进产业化应用;(3)拓展紫椴作为城市绿化树种的选育(以树形、叶色等绿化指标为育种目标)与推广应用;(4)深化紫椴药用活性成分(如黄酮类物质)的分离纯化、药理机制研究及相关药物研发,为紫椴资源的多功能开发提供科学支撑。 展开更多
关键词 紫椴 低温胁迫 光照强度 立地因子 间伐强度 遗传改良 扦插 组织培养
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异地研发中心设立对企业全要素生产率的影响研究 被引量:4
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作者 程晨 穆靖昊 后青松 《经济问题》 北大核心 2025年第3期1-13,91,共14页
在新时代中国经济高质量发展的要求下,利用2009—2023年上市公司数据样本,考察了异地研发中心设立对企业全要素生产率的影响。研究发现:企业设立异地研发中心能够显著提升其全要素生产率,并且是通过拓展技术领域和提高创新质量的路径实... 在新时代中国经济高质量发展的要求下,利用2009—2023年上市公司数据样本,考察了异地研发中心设立对企业全要素生产率的影响。研究发现:企业设立异地研发中心能够显著提升其全要素生产率,并且是通过拓展技术领域和提高创新质量的路径实现的。进一步,在大型企业、国有企业、非高新技术行业的企业以及技术能力较强的企业中,异地研发中心设立对企业全要素生产率的提升效果更加凸显。为缓解反向因果和不可观测因素引致的内生性问题,进行了基于工具变量、倾向得分匹配和双重差分模型的因果识别,并排除了市场拓展效应和融资效应的竞争性假设,研究结论依然成立。研究检验了异地研发中心设立对企业全要素生产率的促进作用,能够为企业提高全要素生产率提供经验证据,有利于政府制定鼓励企业高质量发展的政策,为经济发展注入新动能。 展开更多
关键词 异地研发中心 企业全要素生产率 知识吸收 创新质量
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