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1.
“母乳最好”的宣传话语在目前育龄人群中几乎耳熟能详,但很多信奉科学育儿、希望母乳喂养的都市女性却发现母乳喂养困难重重,其中遭遇“母乳不足”的案例较为多见。回顾历史发现,“母乳不足”的现象全球普遍存在,这个话题在20世纪80年代的英语学术圈曾引起热议。经过十余年讨论后,学者们基本认同大部分遭遇母乳不足的女性并不是真正的“母乳不足”,而是由于种种社会文化因素干扰造成母乳喂养失败的这一结论,其中产后初期的奶瓶介入是重要原因。术语也由insufficient milk syndrome变为perceived insufficient milk,以此来强调“母乳不足”不是一种病理现象,而更多是一种文化感知。  相似文献   
2.
目的: 探讨加替沙星(GAT)对小鼠肝脏的损伤作用及其机制。方法: 选取32只SPF级雄性昆明小鼠作为研究对象,随机分为4组:低、中、高剂量(分别为25、50、100 mg/kg) GAT组和对照组。给药体积按10 mL/kg,连续灌胃给药7 d,对照组给予对应体积的生理盐水。通过检测各组小鼠血清中的谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(AKP)、肌酐(CRE)和甘油三酯(TG)浓度,初步评价加替沙星导致的小鼠肝组织损伤。进一步利用转录组测序技术检测各组小鼠肝脏的基因表达谱,筛选差异表达基因,对差异基因进行基因本体论(GO)功能分类,并采用京都基因与基因组百科全书(KEGG)数据库进行信号通路富集分析。结果: 与对照组比较,高剂量GAT组小鼠肝脏质量显著降低(P<0.01);低、中剂量GAT组肝脏系数显著降低(P<0.01);低、中剂量GAT组小鼠血清ALT浓度显著降低(P<0.05或0.01);低剂量GAT组小鼠血清AST浓度显著降低(P<0.01)。与对照组比较,中剂量GAT组共筛选出27个差异表达基因(包括20个上调基因,7个下调基因)。GO功能分类提示这些基因主要富集在免疫系统、多细胞生物、多生物及生殖过程等17个生物过程中。KEGG通路分析提示差异基因主要富集于脂质代谢、萜类化合物和聚酮化合物的代谢等22条通路中。结论: GAT可导致小鼠肝功能发生变化,并通过影响小鼠肝脏内胆汁酸和胆固醇等内分泌系统和脂质代谢等的平衡,造成肝组织损伤。  相似文献   
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Due to limitations in disease prevalence and hospital specificity, spectral data are often collected with unbalanced sample size. To solve this problem, a new sampling method – grouped-sampling was proposed in this research, which is shown to be effective for unbalanced data. It avoids over-fitting of over-sampling and overcomes under-sampling utilization of under-sampling. In this study, we applied grouped-sampling to two unbalanced datasets where the sample proportions are 199:40 and 75:225. And then verified from two classic models: PCA-SVM (Principal Component Analysis-Support Vector Machine) and the deep learning algorithm GoogLeNet. The accuracy of these two datasets were 85.11% and 96.15% in PCA-SVM and 85.10% and 84.61% on GoogLeNet. Also, the F1-score were evaluated to measure the classification balance of sampling method, and result shows that F1-score of grouped-sampling is always the highest compared to over-sampling and under-sampling. In summary, compared to traditional sampling methods, grouped-sampling performs better on prediction for classes with smaller sample size, which means grouped-sampling can improve the balance of classification results and the potential of practical application. Therefore, we develop a group sampling method that distinguishes between under- and over-sampling, which greatly improves the accuracy and balance of predictions for unbalanced samples.  相似文献   
5.
While a large body of evidence has examined hospital concentration, its effects on health care for low-income populations are less explored. We use comprehensive discharge data from New York State to measure the effects of changes in market concentration on hospital-level inpatient Medicaid volumes. Holding fixed hospital factors constant, a one percent increase in HHI leads to a 0.6% (s.e. = 0.28%) decrease in the number of Medicaid admissions for the average hospital. The strongest effects are on admissions for birth (-1.3%, s.e. = 0.58%). These average hospital-level decreases largely reflect redistribution of Medicaid patients across hospitals, rather than overall reductions in hospitalizations for Medicaid patients. In particular, hospital concentration leads to a redistribution of admissions from non-profit hospitals to public hospitals. We find evidence that for births, physicians serving high shares of Medicaid beneficiaries in particular experience reduced admissions as concentration increased. These reductions may reflect preferences among these physicians or reduced admitting privileges by hospitals as a means to screen out Medicaid patients.  相似文献   
6.
This paper tests for the presence of job lock and “health insurance plan lock” stemming from the health shock of a child family member. Using the onset of an acute, unanticipated health shock, I estimate a 7–14 percent decreased likelihood of all family members leaving their current health insurance network and health plan within one year of the emergency. This corresponds to a reduced one-year job mobility rate of approximately 13 percent for the health plan’s primary policyholder. Furthermore, the non-portability of health insurance products may contribute to the observed job and health plan lock.  相似文献   
7.
目的:采用简单重复序列(SSR)分子标记技术对广西苦玄参主产区69份苦玄参种质样本进行遗传多样性及亲缘关系分析,并筛选与苦玄参苷含量相关联的优良种质基因。为苦玄参种质资源评价、遗传进化分析及分子标记辅助育种等提供依据。方法:基于转录组测序技术,开发20对引物进行批量扩增。利用各标记位点的遗传多态信息,分析69份苦玄参种质的遗传多样性及亲缘关系,并通过一元线性和多元逐步回归分析,筛选与苦玄参苷含量相关联的分子标记。结果:20对SSR引物共扩增出76个等位基因,平均每个位点观测等位基因3.8个,高于有效等位基因数(1.9692个),稀有等位基因率为38.2%,等位基因分布不均匀。等位基因多态率范围为0~59%,平均38.24%,各位点多态率差异较大。各位点多态信息含量(PIC)变化范围为0~0.6211,平均0.3780;Shannon多态性信息指数变化范围为0~1.2401,平均0.7590;Nei’s基因多样性指数(Nei)变化范围为0~0.6823,平均0.4409;以上3个指标最高的为P21,最低为P7,各位点遗传多样性存在较大差异。各位点平均观测杂合度为0.3824,低于平均期望杂合度(0.4425),表现为杂合子缺失;平均遗传分化系数Fst为0.3659;基因流Nm平均值为0.4332,种质遗传分化较大,基因流较小。一元线性回归分析和多元逐步回归分析结果表明,与苦玄参苷IA和IB相关的位点各有5个,其中仅有1个位点与2个成分的含量均相关。结论:20个SSR标记位点遗传多样性存在较大的差异,供试69份种质遗传分化大,基因流较小;从供试20个SSR标记中筛选出9个与苦玄参苷含量相关联的标记位点,试验结果可为苦玄参遗传进化分析及良种选育和繁育等提供依据。  相似文献   
8.
PurposeWithin the specialty of prosthodontics, oral impressions are ubiquitous tools utilized to transfer intraoral characteristics such as teeth, implants, and soft tissue into a physical state (stone cast) that is processable in a laboratory setting for the fabrication of dental restorations. In recent years, optical impression systems have become ubiquitous in clinical practice replacing the conventional method of impression making. The purpose of the present study was to evaluate the feasibility and accuracy of computerized optical impression making of edentulous jaws in an in vivo setting.Methods29 edentulous patients (27 maxillae and five mandibles) underwent conventional impressions as well as computerized optical impressions. The conventional impressions and the resulting stone casts were digitized and superimposed over the computerized/digitized optical impressions in order to obtain information on differences between the two datasets. Statistical analyses were performed to identify relevant deviations.ResultsThe overall mean difference between the stone cast, digital scans and the computerized optical scans were 336.7 ± 105.0 µm (n = 32), 363.7 ± 143.1 µm (n = 24), and 272.1 ± 168.5 µm (n = 29), respectively. The visual evaluations revealed highest deviations (≥ 500 µm) in the areas of the soft palate, the sublingual areas, and the vestibule (peripheral seal zone).ConclusionsWithin the limitations of the present study, the investigated scanners were not able currently to fully replace a conventional impression for the fabrication of a complete denture.  相似文献   
9.
《Vaccine》2020,38(39):6153-6161
Pseudorabies Virus (PRV) is the causative agent of Pseudorabies (PR), also known as Aujeszky’s Disease, one of the most important infectious diseases in swine, resulting in huge economic losses to the swine industry globally. The emergence of mutant PRV strains after 2011 resulted in a sharp decrease in the efficacy of available commercial vaccines. To develop a more effective vaccine that can prevent the spread of PRV, glycoprotein B (gB), glycoprotein C (gC) and glycoprotein D (gD) from recent PRV isolates were expressed in a baculovirus system and their protective efficacy was tested in mice and piglets. Neutralizing antibody titers (NAs) in mice vaccinated with gB, gC and gD peaked at 28 days after immunization and then slowly declined. NAs in the mice immunized with gD were remarkably higher than other groups. After a lethal challenge of 5 LD50 with mutant PRV-HNLH strain, the survival rates of gB and gD were 100% and 87.5% respectively, which was significantly higher than gC group (50%). Piglets vaccinated with the gD and gB + D vaccines developed the highest NAs 7 days post immunization. No piglets in these two groups exhibited clinical symptoms, high body temperature or virus shedding following challenge with 106.6 TCID50 with the mutant PRV-HNLH strain. Histopathology and immunohistochemistry showed remarkably reduced pathological damage and viral loads in gD and gB + D groups. Furthermore, the duration of the NAs induced by gD vaccine could maintain as long as four months after a single dose. The current study indicates that a gD-based vaccine could be developed for the efficient control of PRV.  相似文献   
10.
Background: As the demand for traditional Chinese medicinal materials increases in China and even the world, there is an urgent need for an effective and simple identification technology to identify the origin and quality of the latter and ensure the safety of clinical medication. Mineral element analysis and isotope finger-printing are the two commonly used techniques in traditional origin identification. Both of these techniques require the use of stoichiometric methods in the identification process. Although they have high accuracy and sensitivity, they are expensive and inefficient. In addition, near-infrared spectroscopy is a fast, nondestructive, and widely used identification technique developed in recent years, but its identification results are susceptible to samples’ states and environmental conditions, and its sensitivity is low. Hyperspectral imaging combines the advantages of imaging technology and optical technology, which can simultaneously access the image information and spectral information which reflect the external characteristics, internal physical structure, and chemical composition of the samples. Hyperspectral imaging is widely applied to agricultural product inspection, but research into its application in origin and quality identification of TCM materials is rare. Methods: In this study, the algorithm framework discriminative marginalized least squares regression (DMLSR) was used for feature extraction of frankincense hyperspectral data. The DMLSR with intraclass compactness graph and manifold regularization can efficiently learn the projective samples with higher separability and less redundant information than the original samples. Then, the discriminative collaborative representation with Tikhonov regularization (DCRT) was applied for classifying the geographical origin and level of frankincense. DCRT introducesthe discriminant regularization term and incorporates SID, which is more sensitive to the spectrum as the measurement method and is more suitable for the frankincense spectral data compared with SVM. Results: For the origin classification task, samples of all levels from each origin were, respectively, selected for three?way classification. We used 10-fold cross-validation to select a model parameter in the experiment. When obtaining the optimal parameters, we randomly selected the training set and testing set, where the training set accounts for 70% and the training set for 30%. After repeating this random process 10 times, we obtained the final average classification accuracy, which is higher than 90%, and the standard deviation fluctuation is usually small. For the level classification task, samples of each level from three origins were separately selected for multiclassification. We randomly selected the training set and testing set from each origin. The level classification results of the three origins are good on D4350 data, and the classification accuracy of each level is basically above 80%. Conclusion: Experiments and analysis show that our algorithm framework has excellent classification performance, which is stable in origin classification and has potential for generalization. In addition, the experiments show that in our algorithm framework, different classification tasks need to combine different data sources to achieve better classification and recognition, as the origin classification task uses frankincense’s D3000 data, and level classification task uses frankincense’s D4350 data.  相似文献   
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