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91.
92.
Biochar application has been reported to improve the physical, chemical, and hydrological properties of soil. However, the information about the size fraction composition of the applied biochar as a factor that may have an impact on the properties of soil-biochar mixtures is often underappreciated. Our research shows how sunflower husk biochar (pyrolyzed at 650 °C) can modify the water retention characteristics of arable sandy soil depending on the biochar dose (up to 9.52 wt.%) and particle size (<50 µm, 50–100 µm, 100–250 µm). For comparison, we used soil samples mixed with biochar passed through 2 mm sieve and an unamended reference. The addition of sieved biochar to the soil caused a 30% increase in the available water content (AWC) in comparing to the soil without biochar. However, the most notable improvement (doubling the reference AWC value from 0.078 m3 m−3 to 0.157 m3 m−3) was observed at the lowest doses of biochar (0.95 and 2.24 wt.%) and for the finest size fractions (below 100 µm). The water retention effects on sandy soil are explained as the interplay between the dose, the size of biochar particles, and the porous properties of biochar fractions.  相似文献   
93.
The role of different parameters (including genetic factors) on the timing and extend of left ventricle hypertrophy in patients with aortic stenosis is not defined. In our study we analyze the influence of clinical, echocardiographic parameters and I/D polymorphism of the angiotensin converting enzyme gene on the left ventricle hypertrophy (left ventricle mass index) in this group of patients. The study was done with the group of 302 pts with aortic stenosis--120 women and 182 men; mean age 58 +/- 11 yrs. Stepwise (backward) regression was used to assess the influence of the analyzed parameters (age, gender, history of hypertension, EF, MGA, presence of significant coronary artery disease and I/D ACE polymorphism) on the LVH in the all pts and in the women and the men separately. In the whole group the LVMI depends on EF (t = -6.5; p = 0.0001--higher LVMI in lower EF), MGA (t = 3.9; p = 0.0001--higher LVMI in higher MGA) and gender (t = 2.8; p = 0.005--higher LVMI in men). In women LVMI was related with EF (t = -3.6; p = 0.001--higher LVMI in lower EF), age (t = 2.9; p = 0.004--higher LVMI in older pts) and MGA (t = 2.5; p = 0.013--higher LVMI in higher MGA). In men the LVMI depends on EF (t = -4.8; p = 0.0001--higher LVMI in lower EF) and MGA (t = 1.98; p = 0.049--higher LVMI in higher MGA). Significant relationship between LVMI and results of I/D ACE polymorphism was observed both in women and men. I/D polymorphism relationship with LVMI was divergent in these 2 groups--association of higher LVMI with lack of DD type of polymorphism in women and presence of DD polymorphism in men. CONCLUSIONS: 1. Left ventricle hypertrophy in pts aortic stenosis is higher in men than in women. 2. In women left ventricle hypertrophy is related with ejection fraction, maximal aortic gradient, age and I/D ACE polymorphism; in men it is related to EF, MGA and I/D ACE polymorphism. 3. The influence of I/D ACE polymorphism on the left ventricle hypertrophy is divergent in women and men--in women related to the lack of DD polymorphism, in men related to the presence of DD polymorphism.  相似文献   
94.
Background: The relation between postinfarction left ventricle remodeling (LVR), autonomic nervous system and repolarization process is unclear. Purpose of the study was to assess the influence of LVR on the early (QTpeak) and late (TpeakTend) repolarization periods in patients after myocardial infarction (MI) treated with primary PCI. The day‐to‐night differences of repolarization parameters and the relation between QT and heart rate variability (HRV) indices, as well left ventricle function were also assessed. Methods: The study cohort of 104 pts was examined 6 months after acute MI. HRV and QT indices (corrected to the heart rate) were obtained from the entire 24‐hour Holter recording, daytime and nighttime periods. Results: LVR was found in 33 patients (31.7%). The study groups (LVR+ vs LVR?) did not differ in age, the extent of coronary artery lesions and treatment. Left ventricle ejection fraction (LVEF) was lower (38%± 11% vs 55%± 11%, P < 0.001), both QTc (443 ± 26 ms vs 420 ± 20 ms, P < 0.001) and TpeakTendc (98 ± 11 ms vs 84 ± 12 ms, P < 0.005) were longer in LVR + patients, with no differences for QTpeakc. Trends toward lower values of time‐domain (SDRR, rMSSD) HRV parameters were found in LVR+ pts. Day‐to‐night difference was observed only for SDRR, more marked in LVR‐group. Remarkable relations between delta LVEF (6 months minus baseline), delta LVEDV and TpeakTendc were found, with no such relationships for QTpeakc. Conclusions: The patients with LVR have longer repolarization time, especially the late phase‐ TpeakTend, which represents transmural dispersion of repolarization. Its prolongation seems to be related to local attributes of myocardium and global function of the left ventricle but unrelated to the autonomic nervous influences. Remodeling with moderate LV systolic dysfunction is associated with insignificant decrease in HRV indices and preserved circadian variability.  相似文献   
95.
Heme oxygenase-1 (HO-1) is a stress protein that has been suggested to participate in defense mechanisms against agents that may induce oxidative injury, such as heme and inflammatory molecules. Incubation of endothelial cells in a high-glucose (33 mmol/L) medium for 7 days resulted in a decrease of HO activity by 34% and a decrease in HO-1 and HO-2 proteins compared with cells exposed to low glucose (5 mmol/L) (P<0.05) or cells exposed to mannitol (33 mmol/L). Overexpression of HO-1 was coupled with an increase in HO activity and carbon monoxide synthesis, decreased cellular heme, and acceleration in all phases of the cell cycle (P<0.001). The rate of cell cycle or cell birth rate was increased by 29% (P<0.05) in cells overexpressing HO-1 but decreased by 23% (P<0.05) in cells underexpressing HO-1 compared with control cells. Exposure to high glucose significantly decreased cell-cycle progression in control cells and in cells underexpressing HO-1 but did not decrease cell-cycle progression in cells overexpressing HO-1. High glucose induced p21 and p27 in control cells but not in cells overexpressing HO-1. The addition of tin-mesoporphyrin (SnMP), an inhibitor of HO activity, reversed the HO-1-mediated decrease of p21 and p27 in cells overexpressing HO-1. These findings identify a novel effect of HO-1 on endothelial cell growth and indicate that heme metabolism and HO-1 expression regulate signaling systems in cells exposed to high glucose, which controls cell-cycle progression.  相似文献   
96.
Nitric oxide (NO) synthesized froml-arginine interacts with prostaglandins (PG) and sensory neuropeptides in the regulation of mucosal integrity, but the role ofl-arginine, a substrate for NO-synthase, in gastroprotection and healing of chronic gastric ulcers has been little studied. In this study we compared the effects of intragastric (i.g.) and systemic (i.v.) administration ofl-arginine ord-arginine on gastric secretion and acute gastric lesions provoked in rats by i.g. application of 100% ethanol, acidified aspirin (ASA), or the exposure to 3.5h of water immersion and restraint stress (WRS). In addition, the effects ofl-arginine on ulcer healing and the formation of new vessels (angiogenesis) were determined, using monoclonal antibody (MAb E-9).l-arginine (10–200 mg/kg i.g.) failed to significantly affect gastric secretion but dose-dependently reduced the gastric lesions induced by 100% ethanol, ASA, and WRS, the doses inhibiting 50% of these lesions being 65, 94, and 72 mg/kg, respectively. This protection was accompanied by a significant rise in the gastric blood flow (GBF), whereasl-arginine given i.v. failed to affect the ethanol-lesions and the GBF.d-arginine or the NO-related amino acids—l-glutamine,l-citrulline, orl-ornithine—failed to significantly influence these lesions. Suppression of the generation of mucosal PG by indomethacin or capsaicin-denervation attenuated the protection and hyperemia induced byl-arginine. The inhibition of constitutive NO synthase byl-NNA had no significant effect on the protection afforded byl-arginine, but reduced the gastric hyperemia accompanying this protection.l-arginine (150 mg/kg per day, i.g.) accelerated the ulcer healing and increased GBF at the ulcer margin, and angiogenesis, whereas treatment with L-NNA had an opposite effect.l-arginine added to NG-nitro-l-arginine (L-NNA) restored the ulcer healing, hyperemia, and angiogenesis. We conclude that: (1) the protective activity ofl-arginine involves gastric hyperemia mediated by NO and a mild irritant effect due to enhanced generation of endogenous PG, and (2) the ulcer healing properties ofl-arginine depend upon its hyperemic and angiogenic actions, possibly involving NO.  相似文献   
97.

Objectives

Recently in Poland as a result of the high rate of aging population and high rates of morbidity, a growing demand for the physiotherapist profession is observed. The results of this study can be used to formulate principles for better organization of physiotherapist’s workplace in order to prevent occurrence of burnout. The aim of this study is to investigate the effect of gender on satisfaction with life and burnout among active physiotherapists.

Material and Methods

The survey was anonymous and voluntary, and involved a group of 200 active physiotherapists working in health care units and educational centers in Po?land. The study group was selected randomly and incidentally. Each respondent received a demographic data sheet and a set of self-rating questionnaires (Life Satisfaction Questionnaire, Burnout Scale Inventory).

Results

Burnout among men decreased along with increasing satisfaction with one’s work and occupation, friends, relatives and acquaintances, sexuality, and increased due to greater satisfaction with one’s housing status. Burnout among women decreased along with increasing satisfaction with one’s health, free time and friends, relatives and acquaintances, and increased due to work at a setting other than a health care unit or educational center. Statistical analysis failed to reveal any significant differences with regard to the BSI domains and with regard to the overall burnout index as well as with regard to the assessment of satisfaction with life between female and male physiotherapists.

Conclusions

Satisfaction with children, marriage and partnership, with one’s work and occupation, interactions with friends, relatives and acquaintances and sexuality may contribute to reduction of burnout among men. Women who are satisfied with their children, family, health, free time and contacts with friends, relatives and acquaintances are less prone to burnout. Weak financial situation among women and deficiency of free time among men can induce burnout. Improving staff happiness may contribute to decreasing burnout.  相似文献   
98.
Replication-dependent histone mRNAs end with a conserved stem loop that is recognized by stem-loop–binding protein (SLBP). The minimal RNA-processing domain of SLBP is phosphorylated at an internal threonine, and Drosophila SLBP (dSLBP) also is phosphorylated at four serines in its 18-aa C-terminal tail. We show that phosphorylation of dSLBP increases RNA-binding affinity dramatically, and we use structural and biophysical analyses of dSLBP and a crystal structure of human SLBP phosphorylated on the internal threonine to understand the striking improvement in RNA binding. Together these results suggest that, although the C-terminal tail of dSLBP does not contact the RNA, phosphorylation of the tail promotes SLBP conformations competent for RNA binding and thereby appears to reduce the entropic penalty for the association. Increased negative charge in this C-terminal tail balances positively charged residues, allowing a more compact ensemble of structures in the absence of RNA.Histone synthesis increases at the beginning of S-phase to package newly replicated DNA with histone proteins, but synthesis must be shut down rapidly and histone mRNA degraded at the end of DNA replication because of the toxicity of surplus histone proteins (1, 2). This cyclic demand for histones requires strict regulation, which is achieved mainly by controlling the synthesis and degradation of histone mRNA (3). Replication-dependent histone mRNAs are the only known cellular mRNAs that are not polyadenylated and instead end with a conserved stem loop (4). Histone mRNAs are generated from longer histone pre-mRNAs as a result of an endonucleolytic cleavage between the stem loop and a purine-rich downstream sequence termed the “histone downstream element” (HDE) (5).Stem-loop–binding protein (SLBP), also known as “hairpin-binding protein” (6), binds to the histone mRNA stem loop, and U7 small nuclear ribonucleoprotein binds to the HDE (7). Other factors, including the endonuclease CPSF-73, are involved in both polyadenylation and histone mRNA 3′-end processing (811). In mammalian nuclear extracts, SLBP is not absolutely required for the biochemical reaction of processing (12). In contrast, cleavage of histone pre-mRNA in Drosophila cells and nuclear extracts requires the binding of SLBP to the stem loop (10, 13).The minimal histone mRNA processing domain of Drosophila SLBP contains a 72-aa RNA-binding domain (RBD) unique to SLBPs and an 18-aa C-terminal region (Fig. 1A) (14). This RNA-processing domain (RPD) is necessary and sufficient for histone mRNA 3′-end processing in vitro (15). The RBDs of human SLBP (hSLBP) and Drosophila SLBP (dSLBP) are phosphorylated at a Thr residue in a conserved TPNK motif (16, 17). The recent crystal structure of hSLBP RBD in complex with histone mRNA stem loop and 3′ hExo, a 3′–5′ exonuclease required for histone mRNA degradation, provided the first molecular insights into the architecture of this complex, and revealed how the hSLBP RBD forms a new RNA-binding motif to interact with the stem-loop RNA (18). On the other hand, how SLBP alone interacts with the RNA or how this interaction might be affected by phosphorylation of the TPNK motif is not known.Open in a separate windowFig. 1.Schematic of the domain architecture of dSLBP (Upper) and amino acid sequence alignment of RPDs of Drosophila and human SLBP (Lower). Domains of SLBP include the N-terminal domain (NTD), RBD, and C-terminal region (C). Amino acid sequences are shown with the RBD sequence in the top two rows and the C-terminal region in the bottom row. T230 in the TPNK motif and phosphorylation sites in the C-terminal region are indicated with boldface and asterisks, respectively; the residues involved in RNA binding are shown in cyan; and acidic residues in the C-terminal region are shown in red.The C-terminal region of dSLBP contains a motif, SNSDSDSD, whose hyperphosphorylation is required for efficient processing of histone pre-mRNA (15). Despite the similarity of hSLBP and dSLBP RBDs (55% identical residues) and their ability to bind identical stem-loop RNA sequences, neither SLBP can substitute for the other to process histone pre-mRNA in nuclear extracts; in fact, hSLBP inhibits processing of Drosophila histone pre-mRNA (15). This incompatibility results from differences in the C-terminal region (Fig. 1). The sequence C-terminal to the RBD in hSLBP is required for processing, but it is longer, has no similarity to the Drosophila sequence, and lacks phosphorylation sites.Here we focused on dSLBP and showed that phosphorylation greatly increases dSLBP binding affinity for the histone mRNA stem loop. Mimicking phosphorylation of the dSLBP RPD by mutation of phosphorylation sites to Glu residues at both the TPNK motif and the C-terminal region also boosted binding affinity relative to the nonphosphorylated dSLBP RPD. Structural studies of both the human and Drosophila SLBP RPD indicated that phosphorylation of the TPNK motif stabilizes the RNA-binding domain, but the C-terminal region is flexible in the protein:RNA complex and does not contact the RNA. Instead, we show that the increased negative charge in the C-terminal region of the dSLBP RPD results in a more compact ensemble of protein conformations in the absence of RNA, thereby increasing RNA-binding affinity by reducing the entropy of the unbound protein.  相似文献   
99.
Although the search for disease biomarkers continues, the clinical return has thus far been disappointing. The complexity of the body’s response to disease makes it difficult to represent this response with only a few biomarkers, particularly when many are present at low levels. An alternative to the typical reductionist biomarker paradigm is an assay we call an “immunosignature.” This approach leverages the response of antibodies to disease-related changes, as well as the inherent signal amplification associated with antigen-stimulated B-cell proliferation. To perform an immunosignature assay, the antibodies in diluted blood are incubated with a microarray of thousands of random sequence peptides. The pattern of binding to these peptides is the immunosignature. Because the peptide sequences are completely random, the assay is effectively disease-agnostic, potentially providing a comprehensive diagnostic on multiple diseases simultaneously. To explore the ability of an immunosignature to detect and identify multiple diseases simultaneously, 20 samples from each of five cancer cohorts collected from multiple sites and 20 noncancer samples (120 total) were used as a training set to develop a reference immunosignature. A blinded evaluation of 120 blinded samples covering the same diseases gave 95% classification accuracy. To investigate the breadth of the approach and test sensitivity to biological diversity further, immunosignatures of >1,500 historical samples comprising 14 different diseases were examined by training with 75% of the samples and testing the remaining 25%. The average accuracy was >98%. These results demonstrate the potential power of the immunosignature approach in the accurate, simultaneous classification of disease.Cancer is the most likely disease for which an early diagnostic would be immediately beneficial. Unfortunately, finding specific biomarkers, especially for cancer, has been complicated by the fact that biological molecules (RNA, DNA, proteins, or peptides) that are uniquely released by a small tumor into the bloodstream are extremely dilute. Classical biomarker assays are based on one-to-one molecular recognition events to detect one or a few specific analytes that are often measured by antibody–protein interactions. There are three fundamental limitations with this approach, all of which are confounded by the dilution problem alluded to above. The first is that the cross-reactivity of such interactions poses a formidable problem in distinguishing diseases. Biology’s promiscuous use of a limited number of homologous sequences, folds, and domains makes specificity difficult. The second is that diseases such as cancer are themselves heterogeneous, and individual response to disease, at a molecular level, can vary considerably. It is unlikely that this level of complexity can be quantitatively assessed by one or a few specific proteins or metabolites in a way that supports robust diagnosis. Third, many of the biomarkers that have been proposed are of low stability or require substantial preassay purification or preparation; these aspects introduce substantial variation into the measured values (1, 2). As a result, although considerable effort has been put into the development of biomarkers, only a small fraction of candidates make it to clinical practice, and the utility of those that are used is sometimes only modest (35). Here, we explore the ability of the immunosignature technology to address the ideal of a simple, comprehensive diagnostic for multiple cancers.An “immunosignature” is the pattern obtained when circulating antibodies in blood are allowed to bind to a large microarray of randomized-sequence peptides affixed to a solid surface (6). Cancers generate neoantigens by virtue of their mutagenic nature, and they tend to release native proteins and biomolecules not normally encountered by the immune system (79). These behaviors can elicit an immune response (6, 10, 11). By virtue of the tremendous amplification afforded by B-cell replication (12), the signal elicited by the disease-specific antigens is massively amplified. In fact, a key aspect of the immunosignature assay is that the blood is greatly diluted before application to the array, such that only the antibodies that have been sufficiently amplified give distinct signals (13).Another somewhat counterintuitive aspect of the method is that the peptide sequences used on the microarray are purposefully not chosen to represent the natural antigens of the antibodies produced in response to disease. In fact, in the arrays of 10,000 peptides used in this study, the peptide sequences were generated with a random number generator. This enables the same microarray to be used for diagnosis of any disease. Despite using random-sequence peptides, monoclonal antibodies generated from a wide variety of antigens show specific patterns of binding on these arrays, to both cognate and noncognate sequences (14, 15). Many of the peptides bound by a monoclonal antibody against a known linear epitope have no obvious sequence similarity to that epitope. Most of the peptides thus identified have demonstrated low affinity in solution for the antibody but are retained on the arrays due to avidity created by close spacing of individual peptides (15).An immunosignature of an individual consists of an overlay of the patterns from the binding signals of many of the most prominent circulating antibodies. Some of the binding signals are present in most individuals (whether sick or healthy), and some are unique to an individual, but if the individual has a disease such as a cancer, a subset of the binding signals will be due to disease-associated antigens that are common to most individuals with the disease (16). An important aspect of this approach is that it senses essentially all antibodies raised to the disease and detects each of the antibodies as separable binding patterns composed of unique molecular recognition elements. This differs from, for example, an ELISA, which might sum the contributions of many different antibodies using a single protein, cell, or virus capsid. Again, from a statistical perspective, the high dimensionality of this readout affords much more specificity than could be obtained from a set of cognate sequences or from an array of the native antigens themselves.Not only does the use of highly dilute blood and random peptide sequences in the immunosignature assay paradoxically give rise to improved sensitivity and specificity but these aspects of the assay also result in several other unique benefits of the immunosignature approach. Because of the dilution (1:500 in these studies), blood proteins other than antibodies do not significantly bind to the arrays, meaning that there is no sample preparation involved other than dilution (17). The dilution ensures the assay is sample-sparing. Finally, the assay is disease-agnostic. The arrays can be used for the simultaneous detection and identification of multiple diseases.It is simultaneous detection and identification of multiple diseases with a single assay that underlies the true potential of this approach as a disruptive force in healthcare. This, combined with the fact that serum antibodies are robust to handling (17, 18) such that a drop of blood can be sent dried on filter paper through the mail (17), should enable frequent, inexpensive monitoring for many different diseases. The goal of the current work is to test the multidisease aspect of immunosignatures rigorously. Although the approach has previously been used to discriminate various subtypes of brain cancer (19), it has not yet demonstrated multiplexed cancer diagnosis. Here, we perform a blinded train/test validation study wherein a group of 120 individuals with five different cancers from various geographic regions was used as a training set to define a multicancer signature. The signature predicted the disease status of a test cohort of equal size and composition. To explore the ability of the approach to discriminate between an even larger set of diseases, 1,516 different individuals spanning 14 different disease cohorts plus a diverse cohort of healthy controls were assayed and the ability to distinguish between these diseases was evaluated.  相似文献   
100.
Clinical Rheumatology - Gastrointestinal complaints of scleroderma (SS) patients are risk factors for impaired nutritional status, so insightful assessment is necessary. The aim was comparison of...  相似文献   
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