Influence of vapor pressure deficit on vegetation growth in China

Vapor pressure deficit(VPD)plays a crucial role in determining plant physiological functions and exerts a substantial influence on vegetation,second only to carbon dioxide(CO_(2)).As a robust indicator of atmospheric water demand,VPD has implications for global water resources,and its significance extends to the structure and functioning of ecosystems.However,the influence of VPD on vegetation growth under climate change remains unclear in China.This study employed empirical equations to estimate the VPD in China from 2000 to 2020 based on meteorological reanalysis data of the Climatic Research Unit(CRU)Time-Series version 4.06(TS4.06)and European Centre for Medium-Range Weather Forecasts(ECMWF)Reanalysis 5(ERA-5).Vegetation growth status was characterized using three vegetation indices,namely gross primary productivity(GPP),leaf area index(LAI),and near-infrared reflectance of vegetation(NIRv).The spatiotemporal dynamics of VPD and vegetation indices were analyzed using the Theil-Sen median trend analysis and Mann-Kendall test.Furthermore,the influence of VPD on vegetation growth and its relative contribution were assessed using a multiple linear regression model.The results indicated an overall negative correlation between VPD and vegetation indices.Three VPD intervals for the correlations between VPD and vegetation indices were identified:a significant positive correlation at VPD below 4.820 hPa,a significant negative correlation at VPD within 4.820–9.000 hPa,and a notable weakening of negative correlation at VPD above 9.000 hPa.VPD exhibited a pronounced negative impact on vegetation growth,surpassing those of temperature,precipitation,and solar radiation in absolute magnitude.CO_(2) contributed most positively to vegetation growth,with VPD offsetting approximately 30.00%of the positive effect of CO_(2).As the rise of VPD decelerated,its relative contribution to vegetation growth diminished.Additionally,the intensification of spatial variations in temperature and precipitation accentuated the spatial heterogeneity in the impact of VPD on vegetation growth in China.This research provides a theoretical foundation for addressing climate change in China,especially regarding the challenges posed by increasing VPD.

Relationship between sleep quality and blood pressure level in nurses performing shift work

Objective:The aim of the study was to evaluate the quality of sleep in nurses performing shift work in therapeutic and surgical depar tments and to establish possible relationships between level of blood pressure(BP)and quality of sleep.Methods:A total of 20 nurses of the therapeutic depar tments and 20 nurses of the surgical depar tments were enrolled in the study.Sleep quality was assessed using the Pittsburgh Sleep Quality Index(PSQI).BP was measured according to the standard protocol using the Korotkoff method;a sphygmomanometer was used for this twice with an interval of 2 min between 10:00 a.m.and 10:30 a.m.The average value for the 2 indicators was calculated.The diagnosis of essential ar terial hyper tension(AH)was established according to the recommendations of the European Association of Cardiology and the European Association of Hypertension(2018).Results:The overall assessment of the sleep quality of the nurses involved in shift work indicates poor sleep quality;this was true in respondents of both the surgical and therapeutic profiles.However,it was observed that the quality of sleep was significantly lower in nurses of the therapeutic departments.Moreover,poor sleep quality was associated with AH,which was diagnosed in 65%of the nurses of the therapeutic departments and 45%of the nurses of the surgical departments,that is,in almost all of the subjects.Herewith,in the nurses of the therapeutic departments,the level of systolic BP exceeded that of the nurses of the surgical departments.Conclusions:Poor sleep quality is a significant risk factor for AH development and is relevant to nurses performing shift work.Additional clinical studies should be conducted to better understand the mechanisms underlying such adverse cardiometabolic outcomes associated with sleep disorders in the health-sector shift workers.

Establishment of Monitoring and Assessment Index System of Land Degradation of Farmland Ecosystems at Small-scale

The research established land degradation monitoring and assessment in- dex system of farmland ecosystem under influence of human activities, including farming system, measures, mulch residuals, fertilizer pollutions, pesticide pollution, irrigation method, salt content of soils, engineering measures of discharging alkali, agricultural protection forests and poverty. The indices of the system are accessible, and convenient for operation, which is suitable for land managers self-monitoring, re- ducing irrational farming activities, improving farmland productivity and preventing farmland degradation.

Effects of body mass index on intraocular pressure and ocular pulse amplitude

AIM: To investigate the effects of body mass index (BMI) on intraocular pressure (IOP) and ocular pulse amplitude(OPA). METHODS: Totally 140 healthy individuals without any systemic diseases were included in the study. BMI (kg/m2) was calculated for every individual. IOP and OPA were measured with Pascal Dynamic contour tonometer (DCT). Blood pressure was also measured along with the DCT. The patients were divided into three groups according to BMI as: Group1, BMI<25; Group2, 25≤BMI<30; Group3, BMI≥30. Mean values of IOP, OPA, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were used in statistical analysis.RESULTS: In Group1, the means of IOP, OPA, were 16.8±2.3mmHg, 2.7±0.7mmHg respectively; and SBP, DBP were 120.0±6.1mmHg, and 77.4±5.6mmHg respectively. In group2, the mean IOP, OPA, SBP, and DBP were found to be 16.6±2.1mmHg, 2.4±0.7mmHg, 121.7±5.3mmHg, and 79.5±4.9mmHg respectively. In group3, the mean IOP, OPA, SBP, and DBP were found to be 17.3±1.7mmHg, 2.1±0.7mmHg, 122.4±5.7mmHg, and 79.7±5.2mmHg respectively. There were no statistically significant difference between groups in terms of IOP, SBP and DBP, while OPA values were significantly lower in group3 (P=0.001). CONCLUSION: Decreased OPA values in individuals with higher BMI may indicate that subjects with higher BMI have lower choroidal perfusion and lower ocular blood flow.

Correlation of Inferior Vena Cava Respiratory Variability Index with Central Venous Pressure and Hemodynamic Parameters in Ventilated Pigs with Septic Shock

Septic shock is a common critical condition, for which effective early fluid resuscitation is the therapeutic focus. According to the 2008 international guidelines for management of severe sepsis and septic shock, resuscitation should achieve a central venous pressure （CVP） of 8-12 mmHg within the first 6 h. However, it is still uncertain about the sensitivity and specificity of CVP in reflecting the cardiac preload. Ultrasonography is a simple, rapid, non-invasive, and repeatable method for the measurement of sensitivity and specificity of CVP and has thus gradually attracted the increasing attention of physicians. It was reported that ultrasonography can show the inferior vena cava diameter, respiratory variability index, and blood volume in patients with sepsis or heart failure.

Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload

Objective To determine whether reduction in central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-load or is due to arterial dilation. Methods We compared effects of NTG with those of lower body negative pressure (LBNP). Hemodynamic measurements were made at rest,during LBNP (10,20 and 30 mmHg,each for 15 min) and after NTG (10,30 and 100 μg/min,each dose for 15 min) in ten healthy volunteers. Cardiac pre-load,stroke volume and cardiac output were assessed by echocardiography. Central pressure augmentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results LBNP (20 mmHg) and NTG (30 μg/min) reduced pre-load (as measured by the peak velocity of the S wave in the superior vena cava) to a similar degree [by (26.8±3.8)% and (23.9±3.4)%,respectively]. Compared to LBNP,NTG reduced systemic vascular resistance [by (32.9±7.5)%,P<0.01],decreased peripheral and central pressure augmentation [by (20.8±3.4)% units and (12.9±2.9)% units,respectively,each P<0.01]. Conclusion These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.

Importance of Ankle/Brachial Pressure Index in Saudi Patients with Coronary Artery Disease

Background: The ankle/brachial pressure index (ABPI) has been shown to be a good marker of systemic atherosclerosis and a powerful predictor of cardiovascular morbidity and mortality. The objective of this study was to determine the importance of measuring ABPI in Saudi patients with coronary artery disease (CAD). METHODS: This is a hospital based cross-sectional study which was conducted on all Saudi patients who underwent coronary angiography without symptoms of peripheral arterial disease at King Fahd Hospital of the University, Al-Khobar Saudi Arabia. All patients underwent measurement of their ABPI. The study was carried out between December 2010 and November 2011. RESULTS: During the study period, two hundred and five patients were included. Fifty-nine (28.8%) patients were Group II (ABPI ≤ 0.90) and the rest was Group I (ABPI > 0.90). Significant correlation was also found between low ABPI and the extent of CAD (mean number of arteries involved in Group I was 1.78 ± 0.83 compared to 2.10 ± 0.736 in Group II p = 0.011). Nevertheless, the correlation between low ABPI, and the severity of presentation of CAD were also significant (Incidence of myocardial infarction with congestive heart failure was 0.5% in Group I compared to 12% in Group II p CONCLUSION: The ABPI is an important prognostic indicator for Saudi patients with CAD.

Study on Landscape Pattern Index-based Connectivity Analysis of the Primary Farmland Protection Zones

Farmland and primary farmland protection are important contents of land management and land use planning of China. In the new round of land use planning and database construction, primary farmland protection zones are required to have high integrity and connectivity. Using landscape pattern indexes, the integrity and connectivity of primary farmland protection zones was studied in Licheng District of Jinan City. The results showed that, except patch area standard deviation, the other indexes including average patch area, patch area variation coefficient, patch edge density, largest patch index, and mean euclidean nearest-neighbor, all indicate high connectivity of primary farmland protection zones after layout adjustment. A simple and convenient method for identifying the integrity and connectivity of primary farmland protection zones was supplied.

Association between Systolic Blood Pressure Difference ≥10 mm Hg and Ankle-Brachial Index

Background: In new outpatients, blood pressure should be measured in both arms. A previous study reported that an inter-arm systolic blood pressure difference (ΔSBP) of ≥10 mm Hg is associated with an increased risk of mortality. Aim: The aim was to identify the associations with absolute values of ΔSBP (|ΔSBP|) ≥10 mm Hg. Subjects and Methods: This study included 2481 patients. Patients with a body mass index ≥25 kg/m2 were defined as obese. The group of A was defined as following: ankle-brachial index (ABI) was <0.9 or ≥1.3. ΔSBP was expressed as right arm BP minus left arm BP. |ΔSBP| ≥10 mm Hg were analyzed using multivariate logistic analysis. Results: |ΔSBP| ≥10 mm Hg was found in 6.0% of patients and |ΔSBP| < 5 mm Hg in 80.4%. In multivariate analysis, the odds ratios (ORs) of the associations with |ΔSBP| ≥10 mm Hg were significantly associated with abnormal ABI and obesity regardless of sex and age. Moreover, the OR of the combined effects of abnormal ABI and obesity was higher than that of abnormal ABI and obesity alone. Conclusion: |ΔSBP| ≥10 mm Hg was associated with abnormal ABI and obesity. In a primary care setting, blood pressure should be actively measured in both arms. This study suggests that the associations with |ΔSBP| ≥10 mm Hg may be a useful part of screening for abnormal ABI.

Hemodynamic Profiling Using a Cardiac Index–Systemic Vascular Resistance Plot in Patients with Fontan Circulation

Background: Elevated Fontan pressure (FP) alone cannot fully predict clinical outcomes. We hypothesized thathemodynamic profiling using a cardiac index (CI)-systemic vascular resistance (SVR) plot could characterize clinicalfeatures and predict the prognosis of post-Fontan patients. Methods: We included post-Fontan patients whounderwent cardiac catheterization at age < 10 years. Patients were classified into four categories: A, CI ≥ 3, SVRindex (SVRI) ≥ 20;B, CI < 3, SVRI ≥ 20;C, CI ≥ 3, SVRI < 20;and D, CI < 3, SVRI < 20. The primary outcome wasfreedom from the combined endpoint: new onset of protein-losing enteropathy or plastic bronchitis, heart transplant,and death. Clinical and hemodynamic variables and freedom from the endpoint were compared betweenthe hemodynamic categories and outcome predictors were evaluated. Results: Eighty-three patients wereincluded. Median follow-up was 5.3 years. Category A/B/C/D consisted of 4/15/53/11 patients, respectively. Allthe patients in category A were New York Heart Association I/II and had a significantly lower pulmonary vascularresistance index (PVRI). Patients in category C had lower pulmonary/systemic blood flow. Patients in category Dhad a higher PVRI and had the poorest freedom from the endpoint (44% at 5 years). Elevated FP and category Dwere outcome predictors. Conclusions: CI-SVR plots was a novel adjunctive method for Fontan hemodynamicprofiling.

Effect of Low and High Glycemic Index Meals on Hunger and Satiety

Recently, people suffer from the inability to maintain weight with an increasing body mass, and this may be due to several reasons, including the type and quantity of food. In current study, the effect of the glycemic index of foods (high-low-medium) on the speed of return of hunger in adult women was discussed. Non-pregnant or lactating women who do not suffer from chronic diseases such as diabetes and pressure, for three days in a row for breakfast, lunch, and dinner, by calculating the number of hours preceding the feeling of hunger, as the results showed that the least hours of hunger were after eating foods with a low glycemic index and then followed by foods with a medium glycemic index, and the number of hours of starvation after eating foods with a high glycemic index was the least, and this leads to an increase in subsequent food intake and an increase in calories during the day. The results indicated: first day that are high in the glycemic index (breakfast). Highest percentage of feeling hungry was 30% after 4 h (lunch). The highest percentage of feeling hungry was 30% after 3 h, (dinner), the highest percentage of not feeling hungry by 50%. The second day with a low glycemic index (breakfast). The highest percentage of feeling hungry after 4 h was 30%, (lunch). The highest percentage of feeling hungry after 4 h was 30%, (dinner). The highest percentage of not feeling hungry was 80%. Third day with a medium glycemic index (breakfast). The highest percentage of feeling hungry was after 3 h and 4 h, with a percentage of 30%, (lunch), the highest percentage of feeling hungry after 4 h, with a percentage of 30%, (dinner), the highest percentage of not feeling hungry by 70%, which increases body mass and weight continuously, and this leads to an increase in vulnerability to chronic diseases. Therefore, it is important to preserve and be careful to eat meals with a low and medium glycemic index in the diets, with the addition of foods with a high glycemic index, without negligence or excess, and we look forward to increasing the research on the effect of the glycemic index of food on the speed of return of hunger while standardizing the quantity and type of food for all volunteers.

中国农田磷流失风险评价及其关键驱动因素

农田面源磷流失是农业面源污染的重要原因之一,识别流域内农田磷流失风险的关键源区及其影响因子是面源污染控制的重要手段。基于磷指数模型开展2000—2020年中国农田磷流失风险评估,选取土壤有效磷含量、磷肥施用量为源因子,土壤侵蚀模数、年径流深、农田和水体间归一化距离指数为迁移因子,结合GIS技术评估了中国农田磷流失的关键源区;在此基础上,利用随机森林法分析影响中国农田磷流失的关键因子,并通过结构方程模型揭示了农田磷流失风险指数与各因子的关系。结果表明:1)2000—2020年中国农田的磷流失的低、中、高、极高风险面积分别占农田总面积的43.8%、40.5%、13.4%、2.4%。2)中国农田磷流失在2000、2005、2010、2015、2020年高风险和极高风险总面积的年平均占比从大到小依次为:淮河流域、长江流域、珠江流域、东南诸河流域、松辽河流域、西南诸河流域、黄河流域、内陆河流域、海河流域。3)影响农田磷流失风险的关键源因子和迁移因子分别为土壤有效磷含量和归一化距离指数,其重要性特征值分别为129.53和65.12,土壤有效磷含量是农田磷流失最主要影响因子。4)磷流失风险指数与源因子指数、迁移因子指数呈极显著正相关,选取的14个指标对磷指数的解释度达0.62,其中源因子和迁移因子对磷指数的贡献率分别为0.77、0.19(P <0.001)。研究结果可为中国农田磷流失风险评估提供科学参考,对中国农业面源污染的宏观防控及战略决策具有重要意义。

钻井过程中井漏特征精细识别方法研究与应用

井漏是钻井工程中普遍存在的井下复杂问题,严重影响着钻井施工安全与钻井周期,井漏特征精细识别是高效治理井漏的关键。首先,综合测井、钻井、录井及地质等资料,结合漏层力学性质与物理机理分析,利用加权系数法,建立了基于“井漏综合指数”的井漏层位识别新方法。然后,研究了漏失通道类型及尺寸、漏失压差、漏失速度等井漏特征参数的定量分析方法,并给出计算模型,形成了多信息融合的井漏特征精细识别方法。该方法在X区块进行了实例分析,分析结果表明,X区块实际井资料的处理结果与现场实际漏失地层的层位、漏失类型及漏失速度等井漏特征基本吻合。井漏特征精细识别方法综合考虑了井漏的主要影响因素,利用其可以准确识别漏层的特征,为防漏堵漏技术优化及施工提供科学依据。

基于机器学习的低血压预测指数指导术中血压管理的研究进展

术中低血压与术后不良预后密切相关。基于机器学习的低血压预测指数(HPI)利用有创和无创血压监测在非心脏和心脏手术中可以预测低血压,使术中血压管理由被动处理转变为预防性的主动控制。HPI的血流动力学管理减少了术中低血压的发生。本文从HPI概述、HPI有创和无创血压监测在手术中的应用以及HPI的局限性等方面进行综述。

改良俯卧位通气对急性呼吸窘迫综合征患者呼吸功能及预后的影响

目的 探究改良俯卧位通气对急性呼吸窘迫综合征(ARDS)患者血流动力学、呼吸动力学及预后的影响。方法 前瞻性选取河南大学第一附属医院2020年3月至2022年6月收治的98例ARDS患者作为研究对象,通过随机数字表法分为A、B组。通过随机及前瞻性平行对照临床研究,评价不同通气方式在ARDS患者中的作用,其中A组52例接受改良式俯卧位通气,B组46例接受传统俯卧位通气。对比两组患者干预前、干预后(俯卧位通气4 h后)血流动力学[心率(HR)、平均动脉压、中心静脉压]、呼吸动力学指标[气道阻力、静态肺顺应性(Cst)]、氧合指数及腹腔压力的变化。比较两组患者不良事件发生情况,对所有患者进行3个月随访,比较两组患者病死率情况。结果 (1)A组机械通气时间低于B组,撤机成功率高于B组(P<0.05);(2)干预后,两组患者HR均较干预前上升,干预前后差值具有统计学意义(P<0.05);(3)干预后,两组Cst水平均较干预前上升且A组高于B组,干预前后差值具有统计学意义(P<0.05);(4)干预后,两组腹腔压力均较治疗前上升且A组低于B组,干预前后差值具有统计学意义(P<0.05);(5)A组不良事件总发生率[7.69%(4/52)]低于B组[23.91%(11/46)](P<0.05);(6)随访3个月结果显示,A组病死率[23.08%(12/52)]低于B组[43.48%(20/46)](P<0.05)。结论 改良俯卧位通气对ARDS血流动力学、呼吸动力学及相关指标均有显著的改善效果,不良事件的发生率较低且预后状况良好,值得临床参考借鉴。

TyG指数、血压、血糖相关指标与单纯性超重/肥胖患者早期肾功能损伤的关系

目的:探讨TyG指数、血压、血糖相关指标与单纯性超重/肥胖患者早期肾功能损伤(ERFI)的关系及交互作用。方法:选取2017年1月至2021年12月于郑州大学第一附属医院体检的BMI≥24 kg/m 2者3956例为研究对象,按尿白蛋白与肌酐比值(UACR)分组,<3 mg/mmol为对照组(n=3844),3~≤30 mg/mmol为ERFI组(n=112)。采用Logistic回归分析甘油三酯葡萄糖(TyG)指数、血压和糖化血红蛋白(HbA1c)与ERFI的关联,并进一步分析各因素的交互作用。结果:ERFI组的BMI、收缩压(SBP)、舒张压(DBP)、空腹血糖(FPG)、HbA1c、总胆固醇(TG)、TyG指数高于对照组,HDL-C低于对照组(P<0.05)。TyG指数>8.77(OR=2.138,95%CI:1.411~3.240)、正常血压高值(OR=2.450,95%CI:1.652~3.635)和HbA1c 5.61%~<7.00%(OR=1.510,95%CI:1.024~2.226)是单纯性超重/肥胖患者ERFI的危险因素。TyG指数与血压有交互作用(RERI=1.754,95%CI:-0.126~3.636;APAB=0.405,95%CI:0.068~0.741)。结论:TyG指数≥8.77、正常血压高值和HbA1c 5.61%~<7.00%可增加单纯性超重/肥胖患者ERFI的患病风险,且血压与TyG指数存在交互作用。

老年人群24h动态血压监测中清晨高血压与脑血管储备功能相关性

目的研究老年人群24 h动态血压监测中清晨高血压与脑血管储备功能(CVR)的相关性。方法回顾性选取2021年1月至12月到济南市妇幼保健院行24 h动态血压监测的300例老年受试者,依据监测结果分为A组、B组和C组。A组158例为清晨血压升高的高血压患者,男88例,女70例,年龄(66.02±4.35)岁;B组74例为清晨血压正常的高血压患者,男41例,女33例,年龄(65.42±4.42)岁;C组68例为血压正常者,男37例,女31例,年龄(65.77±4.38)岁。以两侧大脑中动脉屏气指数均值<0.69%为CVR减低,屏气指数均值≥0.69%为CVR正常,将300例受试者分为CVR降低组(52例)和CVR正常组(248例)。比较A、B、C 3组患者的临床资料,CVR指标;比较CVR降低组、CVR正常组一般资料,行单因素分析、多因素分析和相关性分析。采用F检验、独立样本t检验、χ^(2)检验、logistic回归分析和Pearson相关性分析。结果300例24 h动态血压监测的老年受试者,清晨血压升高的高血压患者158例,占52.67%;清晨血压正常的高血压患者74例,占24.67%;血压正常者68例,占22.67%。3组收缩压(24 h均值、日间均值、夜间均值)、晨峰指数:A组>B组>C组(均P<0.05);舒张压(24 h均值、日间均值、夜间均值):A组>B组、C组(均P<0.05),B组、C组舒张压比较,差异均无统计学意义(均P>0.05)。CVR:A组[(21.37±7.89)%]<B组[(25.58±8.14)%]<C组[(28.56±8.10)%](均P<0.05);屏气指数:A组[(0.89±0.23)%]<B组[(1.13±0.21)%]、C组[(1.20±0.24)%](均P<0.05),B组、C组屏气指数比较,差异无统计学意义(P>0.05);脉动指数:A组[(1.49±0.36)]>B组[(1.15±0.31)]、C组[(1.06±0.29)](均P<0.05),B组、C组脉动指数比较,差异无统计学意义(P>0.05)。CVR降低组年龄[(73.14±3.21)岁]、清晨收缩压[(132.42±9.64)mmHg](1 mmHg=0.133 kPa)、清晨舒张压[(68.85±6.59)mmHg]均高于CVR正常组[(64.28±4.36)岁、(121.58±7.26)mmHg、(65.36±7.23)mmHg](均P<0.05)。logistic回归分析结果显示:年龄、清晨收缩压、清晨舒张压均为CVR降低的影响因素(均P<0.05)。清晨收缩压与屏气指数呈负相关(P<0.05),与脉动指数呈正相关(P<0.05);清晨舒张压与屏气指数呈负相关(P<0.05),与脉动指数呈正相关(P<0.05)。结论老年人群24 h动态血压监测中清晨高血压患者占比较大,清晨高血压患者CVR、屏气指数较低,脉动指数较高,清晨收缩压、清晨舒张压均与屏气指数呈负相关,与脉动指数呈正相关。

产销平衡区粮食安全测度与时空特征研究——以云南省为例

[目的]衡量与评估粮食产销平衡区云南省的粮食安全状况,为云南省乃至全国的粮食安全科学探索与地方政府决策提供参考依据。[方法]采用质量系数优化后的耕地压力指数模型对2003—2018年云南省的粮食安全进行定量分析。[结果]从时间上看,云南省粮食安全水平总体上呈上升趋势。从数量上看,16个州(市)中,10个州(市)粮食处于安全状态,占62.50%;6个州(市)粮食安全处于不安全状态,占37.50%。从空间上看,曲靖、大理、保山、红河、文山5州(市)为中度安全,德宏、普洱、临沧、昭通、楚雄5州(市)为低度安全,丽江、昆明2市为低度不安全,西双版纳、玉溪2州(市)为中度不安全,迪庆、怒江为高度不安全,无高度安全地区;粮食安全区域主要集中在云南省东部,其次为西部,粮食不安全区域按不安全程度从高到低依次为东北部、南部及部分中部。[结论]云南省粮食安全形势整体处于不安全状态,但不安全程度较低,属于低度不安全。

海陆交互相软土固结抗剪强度指标变化规律研究

以珠三角地区海陆交互相淤泥质软土为研究对象,通过室内直剪试验探究不同固结压力和固结度下抗剪强度及抗剪强度指标的变化规律,提出抗剪强度及对应指标-固结度-固结压力三维Logistic数学模型。研究结果表明,当固结压力P≥200 kPa、固结度U≥40%时,软土黏聚力(c)和内摩擦角(φ)增长较为明显;当U=100%时,各级固结压力作用下的软土抗剪强度(τ)相较于初始状态分别提高了7.89、12.73、13.50、18.20、22.38 kPa;所给出的三维数学模型可直接计算出某一固结压力和固结度下的抗剪强度指标c、φ、τ。研究成果能够更为准确地评价该地区软土地基逐级加载过程中的整体稳定性。

NICU早产儿无创正压通气护理质量评价指标的构建

目的:构建新生儿重症监护室(NICU)早产儿无创正压通气护理质量评价指标,为临床评价NICU早产儿无创正压通气护理质量提供依据。方法:以“结构-过程-结果”三维质量评价模型为基础,于2023年1月—4月采用德尔菲法对25名专家进行问卷函询,并通过层次分析法确立NICU早产儿无创正压通气护理质量评价指标内容及各指标权重。结果:共开展2轮函询,问卷有效回收率分别为92.0%、100.0%,专家权威系数为0.922,0.928,肯德尔和谐系数为0.156,0.180。最终构建了3级结构模式评价指标,设有一级指标3项、二级指标14项、三级指标78项。结论:构建的无创正压通气护理质量评价指标内容科学、合理,具有较强的专科特色,可为早产儿无创正压通气护理质量评价提供参考依据。