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11.
目的分析中国北方面神经炎患者与气象因素之间的相关性,初步探讨气象因素对面神经炎发病的影响。方法回顾性研究采集北京友谊医院神经内科及北京博爱医院神经内科2007年门诊和急诊收治的298例面神经炎患者的临床资料,并采集北京市气象台2007年逐月逐日平均气温、相对湿度、气压、风速、月平均气温、月平均相对湿度、月平均气压、月平均风速、风冷指数(WCF)等气象要素。分析气象因素与面神经炎发病之间的相关性。结果月平均相对湿度与面神经炎发病呈正相关(r=0.629,P=0.028),而月平均气温、平均气压、平均风速、WCF等未发现与面神经炎发病存在明显相关性(r=0.558,P=0.059;r=-0.509,P=0.091;r=-0.219,P=0.494;r=-0.562,P=0.057)。面神经炎发病并不存在季节性差异。结论月平均相对湿度可能是面神经炎发病的影响因素。 相似文献
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Muna Shrestha Helen Shi Mark Strohmeier Ales Medek 《Journal of pharmaceutical sciences》2021,110(4):1592-1600
Physical or chemical interactions between drug product (DP) components can occur during manufacturing and/or upon storage; and may alter DP shelf life and performance. In this work a new Powder X-ray Diffraction (PXRD) peak was observed in DP under accelerated storage conditions. Due to the complex drug product matrix (including API, polymer, fillers, super disintegrant and lubricant), it was challenging to pinpoint the component(s) responsible for the new peak. In addition to PXRD, other orthogonal techniques including Differential Scanning Calorimetry (DSC), thermogravimetric analysis (TGA), dynamic vapor sorption (DVS), Solid State Nuclear Magnetic Resonance (SSNMR) and Infrared (IR) spectroscopy were employed in this investigation to understand the root cause mechanistically. Specifically, multi nuclei SSNMR (1H, 23Na, 13C) was instrumental in delineating the components of the matrix. We identified the root cause to be an acid base reaction occurring in the DP, whereby sodium ion in sodium stearyl fumarate (SSF) is replaced by proton leading to SSF form conversion. We also identified commercially available SSF to be a hydrate that can dehydrate to an anhydrous form upon heating. In general, the same techniques can be used to investigate interactions of any multi component solid dosage forms. 相似文献
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Stainless steels are used as canister materials for interim storage of spent fuel. Crevice corrosion has proved to be a safety concern of 304L stainless steel spent fuel canisters, when exposed to the saline environments of coastal sites. To study the effects of chloride concentration and test duration on the crevice corrosion behavior, and the effect of relative humidity on the initiation of discrete SCC cracks, a test program was conducted on the 304L steel specimens sprayed with synthetic sea water of 3.5 wt.%. The salt-deposited specimens, wrapped up with a crevice former to form a crevice configuration, were then exposed to an environment at 45 °C with a pre-set 45%, 55%, and 70% relative humidity (RH), for 400 h and 10,000 h, respectively. The surface features and crack morphology of the tested 304L stainless-steel specimens were examined by energy-dispersive spectrometry (EDS) and electron back scatter diffraction (EBSD). For the specimens deposited with a chloride concentration of 1 g/m2, no cracks were found in the corroded regions after 400-h exposure, whereas SCC cracks were observed with the specimens tested for 10,000 h at all three pre-set relative humidity. The specimens tested at the pre-set relative humidity 45% are characterized with discrete SCC cracks, but, on the other hand, those exposed to the environments of 55% and 70% relative humidity show SCC cracks of distinct features. From the results of 10,000-h tests, it is inferred that the chloride concentration threshold for SCC initiation of 304L stainless steel at 45 °C is between 0.1 g/m2 and 1 g/m2. 相似文献
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Background
Nosocomial infections constitute a global health problem.Objectives
To explore the relationship between nosocomial infection rates (NIRs) and climatic factors including temperature and relative humidity in Guangzhou area of China.Methods
30892 patients in our hospital in 2009 were investigated for nosocomial infection status, and the contemporaneous temperature and relative humidity were analyzed statistically. NIRs increased with relative humidity and temperature in central ICU and geriatric department.Results
No statistical differences were found between each quarter of 2009 in the distribution of nosocomial infection sites. There were no statistical differences in the pathogenic species of nosocomial infections between high-temperature and low-temperature months in different departments. NIRs had a correlation with temperature and relative humidity in geriatric department and central ICU.Conclusions
To decrease NIRs and improve health care quality, it is necessary to strengthen the control of temperature and humidity especially for geriatric department and central ICU. 相似文献17.
A roadmap for the selection of a pharmaceutical salt form for a development candidate is presented. The free base of the candidate did not have sufficient chemical stability for development. The initially selected salt form turned out to be undevelopable because it was unstable during scale-up synthesis and storage. The rationale for the new solid form screening and the criteria for selection are discussed. Before the final selection, the pH solubility profiles of the 2 new salts, a benzoate and a besylate, were compared. Atypical solubility behavior was observed for the benzoate salt in hydrochloric acid with and without normal saline. A scheme is proposed illustrating how the pKas of the counterion and active pharmaceutical ingredient, the medium composition, and final pH affect the solubility and solution equilibria of the 2 selected salt forms. This scheme also includes the equilibria between solution and solid phases in different pH ranges. The pharmaceutical importance of this research is that it sheds light on how the acidity of the counterion can affect the solubility of the selected salt form in the gastric environment. With a well-designed formulation strategy, this property potentially can be translated to optimal biopharmaceutical performance of the drug product. 相似文献
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Christian Luebbert Christian Klanke Gabriele Sadowski 《International journal of pharmaceutics》2018,535(1-2):245-252
The bioavailability of poorly-water-soluble active pharmaceutical ingredients (APIs) can be significantly improved by so-called amorphous solid dispersions (ASDs). However, the long-term stability of ASDs might be impaired by API recrystallization and/or amorphous phase separation (APS). So far, no methods have been reported to quantify APS in ASDs. In this work, phase-separation kinetics as well as the compositions of the two amorphous phases evolving due to APS were quantitatively determined for the first time using confocal Raman spectroscopy. Raman spectra were evaluated via non-linear multivariate Indirect Hard Modeling and verified by differential scanning calorimetry and hot-stage microscopy. APS in water-free ASDs of ibuprofen and poly (DL-lactic-co-glycolic acid) was investigated considering the influence of temperature and polymer architecture (linear vs. star-shaped). Water absorbed at 40?°C and 75% relative humidity (RH) promotes APS which was quantified for formulations of felodipine/poly(vinyl pyrrolidone) and ibuprofen/poly(vinyl pyrrolidone). 相似文献
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The effect of relative humidity on the domain structure imaging and polarization switching process of Pb(Zn1/3Nb2/3)O3-x%PbTiO3 (PZN-x%PT) ferroelectric single crystals has been investigated by means of the piezoresponse force microscopy (PFM) and piezoresponse force spectroscopy (PFS) techniques. It was found that the PFM amplitude increases with the relative humidity, and that the ferroelectric hysteresis loops at different relative humidity levels show that the coercive bias decreases with the increase in relative humidity. These observed phenomena are attributed to the existence of the water layer between the probe tip and the sample surface in a humid atmosphere, which could affect the effect of the electric field distribution and screening properties at the ferroelectric sample surface. These results provide a better understanding of the water adsorption phenomena at the nanoscale in regard to the fundamental understanding of ferroelectrics’ properties. 相似文献