Comparative analysis of pressure ulcer development in stroke patients within and outside healthcare facilities: A systematic review and meta-analysis.

The risk of pressure ulcers in stroke patients is a significant concern, impacting their recovery and quality of life. This systematic review and meta-analysis investigate the prevalence and risk factors of pressure ulcers in stroke patients, comparing those in healthcare facilities with those in home-based or non-clinical environments. The study aims to elucidate how different care settings affect the development of pressure ulcers, serving as a crucial indicator of patient care quality and management across diverse healthcare contexts. Following PRISMA guidelines, a comprehensive search was conducted across PubMed, Embase, Web of Science and the Cochrane Library. Inclusion criteria encompassed studies on stroke patients in various settings, reporting on the incidence or prevalence of pressure ulcers. Exclusion criteria included non-stroke patients, non-original research and studies with incomplete data. The Newcastle-Ottawa scale was used for quality assessment, and statistical analyses involved both fixed-effect and random-effects models, depending on the heterogeneity observed. A total of 1542 articles were initially identified, with 11 studies meeting the inclusion criteria. The studies exhibited significant heterogeneity, necessitating the use of a random-effects model. The pooled prevalence of pressure injuries was 9.53% in patients without family medical services and 2.64% in patients with medical services. Sensitivity analysis confirmed the stability of these results, and no significant publication bias was detected through funnel plot analysis and Egger's linear regression test. The meta-analysis underscores the heightened risk of pressure injuries in stroke patients, especially post-discharge. It calls for concerted efforts among healthcare providers, policymakers and caregivers to implement targeted strategies tailored to the specific needs of different care environments. Future research should focus on developing and evaluating interventions to effectively integrate into routine care and reduce the incidence of pressure injuries in stroke patients.

Quantitative structure-toxicity relationship study of lethal concentration to tadpole (Bufo vulgaris formosus) for organophosphorous pesticides.

In the present study more than 1,000 structural parameters of 41 organophosphorus pesticides (OPs) were calculated using the software ChemOffice 8.03 and Dragon 2.1. Then, with multivariate linear regression and best subset regression analyses, different equations were derived to calculate the lethal toxicity, LC(50), for these 41 organophosphorous pesticides found in tadpoles (Bufo vulgaris formosus). An equation was developed for all selected OPs, especially those with relatively low toxicity levels (LC(50)>4.5mM) that accounted for 89.09% of the variability in the toxic effect. The equation indicated that the main contributions to OPs toxicity with tadpoles were the electrostatic contribution qH(+) (maximum net positive H atomic charge), spatial autocorrelation (MATS7 m) and hydrophobicity (lgK(ow)), with the two former being the most important parameters. For OPs with high toxicity, however, different structural parameters were introduced. The following equation was developed with LC(50)<4.5mM. These equations implied that with different levels of toxicity there could have different mechanisms in the tadpole. Furthermore, the results showed that molecular structural parameters had a particular value in modeling chemical reactivity within a homologous series of compounds.

Dicofol application resulted in high DDTs residue in cotton fields from northern Jiangsu province, China.

Dicofol with high impurity of DDT compounds is still widely used in agricultural practice such as cotton cultivation and becomes an important source of DDT pollution in China. In this study, investigations on the DDT residues in cotton fields from northern Jiangsu province, China were conducted. The results showed that DDTs in cotton soil were much higher than other mode of land use. The DDTs levels ranged from 4.2 to 678.6 ngg(-1), with a mean concentration of 190.4 ngg(-1), of which the most abundant compounds were p,p'-DDE (mean of 129.38 ngg(-1)), p,p'-DDT (mean of 26.57 ngg(-1)) and o,p'-DDT (mean of 16.92 ngg(-1)). The concentrations of o,p'-DDT and o,p'-DDE were significantly higher (p<0.05) in topsoil (0-10 cm) than in subsoil (10-20 cm), while other DDT compounds were not. Source apportionment showed that dicofol-type DDT accounted for up to 80% of the DDTs residue. All the results indicated that dicofol applications resulted in serious DDT pollution in cotton fields. Our work provided implications for reasons why there was no apparent decrease of DDT level in China.

Leaf-air transfer of organochlorine pesticides from three selected vegetables.

The leaf-air transfer of organochlorine pesticides (OCPs) in three kinds of vegetables, namely lettuce, romaine and garlic leaves was investigated. It was found that although the uptake of OCPs by the three selected vegetables was similar under controlled conditions, the depuration varied significantly among chemicals and plant species in terms of elimination rate, final residue of each OCPs, as well as the effect of temperature on the residue of OCPs in the vegetables. The results indicated that neither QCB nor HCB could be trapped tightly by any of the three selected vegetables, in contrast, p,p'-DDT could be retained effectively by all of them; the retainment of alpha-HCH, gamma-HCH, p,p'-DDE, was dependent on the vegetable species, of which the garlic leaf had the biggest ability to trap them. Our work provided insight into the behavior of OCPs in the agroecosystem.

QSARs for the toxicity of polychlorinated dibenzofurans through DFT-calculated descriptors of polarizabilities, hyperpolarizabilities and hyper-order electric moments.

DFT-B3LYP method with 6-31G(**) basis set was employed to fully optimize the electronic structures of 135 polychlorinated dibenzofurans and parent compound, namely dibenzofuran. It was demonstrated that polarizability anisotropy and mean polarizability could change sensitively and systematically with chlorine number and substitution pattern. And new quantitative structure-activity relationships (QSARs) focused on the binding affinities of aryl hydrocarbon receptor (AhR), aryl hydrocarbon hydroxylase (AHH) and 7-ethoxyresorufin O-deethylase (EROD) induction potencies of PCDFs were developed. It was concluded that polarizability anisotropy in conjunction with hyperpolarizabilties and hyper-order electric moments, e.g. octupole moments could well interpret the variation of toxicity of different congeners and dispersion interaction should be the leading form among various interactions. Although the terms of hyperpolarizabilities and hyper-order electric moments were not the same significant ones as polarizability anisotropy, the long-range interactions characterized by them should not be ignored in explaining the toxicity.

Bioavailability to grains of rice of aged and fresh DDD and DDE in soils.

DDT had been widely used around the world before 1980s and is still under production and use for non-agricultural purposes in China. Because of their special physicochemical properties, p,p'-DDT and its main metabolites, p,p'-DDD and p,p'-DDE, accumulated and persisted in the environment, presenting potential menace on biota. A green-house study was conducted to determine the bioavailability of p,p'-DDD and p,p'-DDE to grains of rice and the influences of traditional Chinese farming practices on their bioaccumulation. Paddy rice and dry rice were grown in submerged paddy soils and non-submerged upland soils, respectively. Two types of soil, Hydragric Anthrosols (An) and Hydragric Acrisols (Ac), were employed. Bioaccumulation factors (BAFs) of DDE ranged from 0.67 for rice grown in non-submerged An to 0.84 in submerged An in the control group, whilst BAFs were all below 0.04 in experimental groups. BAFs of DDD varied from 1.39 for submerged An to 2.26 for submerged Ac in original soils. In contrast, BAFs were between 0.05 for non-submerged Ac and 0.08 for submerged An in DDD-contaminated soils. Flooding seemed to have two contradictory effects on the DDE/DDD accumulation by rice: on one hand, it made the pollutants more mobile and bioavailable; while on the other hand, it enhanced the degradation and binding of POPs. Adding rice straw to the soils protected DDE from being taken up yet promoted DDD accumulation by rice. Furthermore, the distinct inorganic component of the soils might also play an important role in the environmental activities of POPs.

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China.

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, sigmaDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by sigmaHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and alpha-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD+DDE)/DDT in soils under three land usages were: paddy field > tree land > fallow land, indicating that land usage influenced the degradation of DDT in soils. Ratios of p,p'-(DDD+DDE)/DDT > 1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.

Quantitative structure-toxicity relationships of organophosphorous pesticides to fish (Cyprinus carpio).

This study was conducted to determine the relationships between 1381 chemical and structural parameters of 43 organophosphorus pesticides (OPs) and their toxicity to fish, Cyprinus carpio, using ChemOffice 8.03 and Dragon 2.1. By multivariate linear regression and intervariable regression analyses, various equations have been derived to calculate the lethal toxicity value, LC(50), for 43 OPs found in fish with different levels of toxicity. Results show that for all selected OPs, especially those of low toxic OPs (LC(50)< 2.5 mM), the equation, LC(50) = 56.259 - 13.071 lg K(ow)+17.510 MATS8P-17.455 Mor24u - 0.085 MW + 1.706 (lg K(ow))(2) + 2.306 (Mor14e)(2) + 6.849 Mor20 m (n = 43, F = 36.815, r = 0.942, r(adj)(2) = 0.862, SE = 2.899, p < 10(-6)), could account for 86.2% of the variability of the toxic effect. The steric and electronic characteristics and the hydrophobicity of OPs, in particular, are among the most important parameters determining the toxicity of OPs to fish. For the OPs with high toxicity, different structural parameters were introduced into the following two equations: LC(50)=3.795-1.195 (H1p)(2)-0.037 U-2.225 MATS3v-19.593 Tcon (n = 16, F = 56.820, r = 0.977, r(adj)(2) = 0.937, SE = 0.143, p < 10(-6)), where LC(50) is less than 2.5 mM, and LC(50) = 0.341-0.561 (HOMA)(2) + 0.231 HOMA (n = 3,r(adj)(2) = 1), where LC(50) is less than 0.3 mM. These results suggest that chemical and structural parameters could be useful in modeling chemical reactivity within homologous series of OP compounds and elucidating possible mechanisms associated with different levels of toxicity to fish.

Relationships between humic substance-bound mercury contents and soil properties in subtropical zone.

The bioavailability of humic substance-bound mercury (HS-Hg) has been established, while the distribution of HS-Hg in soils in relation to soil properties remains obscure. Path analysis and principal component analysis were employed in present study to investigate how soil factors influence the contents of HS-Hg in soils. Results showed that HS-Hg ranged from 0.0192 to 0.2051 mg/kg in soils. The two fractions existed in soils as humic acid-bound mercury (HA-Hg) > fulvic acid-bound mercury (FA-Hg) and the ratio of HA-Hg/FA-Hg was 1.61 on the average. Soil organic carbon (OC) and HS favorably determined soil HS-Hg and the two fractions. The mercury source forming HS-Hg derived from soil total mercury and HS-Hg. FA-Hg and HA-Hg served as mercury source for each other. In acidic soils, FA-Hg and HA-Hg consistently rose with the increase of OC, and generally HA-Hg increased more dramatically. Soils with lower pH and lighter texture contained more HS-Hg, particularly fraction of FA-Hg. Among all influencing factors, organic material source showed the strongest effect, followed by other soil properties and soil mercury source.

[QSPR study on the lipid-water partition coefficients of dioxins based on DFT].

With computational method of density functional theory (DFT), quantified model study of equilibrium partitioning properties of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) between lipid phase of organism (Poecilia reticulata) and water phase was carried out based on quantum chemical and further calculated parameters, namely frontier orbital energies, entropies, traceless quadrupole moments as well as molecular absolute hardness, electronegativities and electrophilicity indices, which all were derived from full geometry optimization of PCDD/Fs. Through multiple linear regression (MLR) analyses, quantitative structure-property relationship (QSPR) was successfully proposed in the form of multi-parameter quadratic function: lgK(hw) = 5.343 - 0.001(S - 125.480)(2) - 0.355(omega - 3.239)(2) + 0.006( Q = - 2.950)(2) - 22.728(eta - 2.365)(2). It was shown that the obtained QSPR had higher goodness of fitting and robustness, determination coefficient and cross-validated correlation coefficient being 0.943 and 0.908 respectively, and it was also provided with ideal interior and exterior predictive abilities so that it could be used for prediction of unknown lipid-water partitioning properties. By comparison, QSPR in this research was superior to that from previous SOFA (solubility parameter for fate analysis) method on the whole. Lipid-water partitioning properties (coefficients) of PCDD/Fs should be mainly related to molecular volume and aryl hydrocarbon molecular interactions determined by charge distribution. To a certain degree, they also might be influenced by potential biotransformation and molecular reactivity.

[Effect of low-molecular-weight organic carbon on anaerobic degradation and volatilization of hexachlorobenzene in soils].

Batch incubation experiments in aid of anaerobic incubation flask were conducted to study the anaerobic degradation and volatilization of hexachlorobenzene (HCB), the change of pH in soil, the emission of CH4 and CO2, and the volatilization of HCB in the Hydragric Acrisol and Gleyi-Stagnic Anthrosol added with acetic acid, glucose and citric acid. Results showed that HCB was reduced by 20%-44% in Hydragric Acrisol during 8 weeks, and addition of acetic acid inhibited the dechlorination, indicating that dechlorination was impeded at low pH. Addition of glucose or citric acid decreased the dechlorination rate initially and then increased it. HCB was reduced by 21%-23% in Gleyi-Stagnic Anthrosol, and there was no obvious effect by adding low-molecular-weight organic carbon. The main product of HCB anaerobic dechlorination was pentachlorobenzene (PCB), which were 23-96 microg/kg and 64-92 microg/kg in Hydragric Acrisol and Gleyi-Stagnic Anthrosol respectively. Furthermore, the degradation of HCB had no statistically significant correlation with the productions of CH4 and CO2. Addition of low-molecular-weight organic carbon reduced HCB volatilization, which was stronger in Hydragric Acrisol than in Gleyi-Stagnic Anthrosol, indicating that soil organic matter was an important factor in HCB volatilization.

[Hysteretic characteristics of atrazine desorption from fluvo-aquic soil].

Kinetic batch experiments are carried out in order to investigate the effects of a wide range of atrazine initial concentrations and consecutive desorption time on the desorption characteristics of atrazine from fluvo-aquic soil. The results reveal that, atrazine concentrations in soil solution gradually decreased with desorption time increasing, whose relationship can be expressed with empirically exponential functions. After consecutive five steps (or 5 days), when atrazine initial concentrations increased from 50 microg x L(-1) to 2000 microg x L(-1), the average desorption percentages were 23.1%, 30.4%, 33.0%, 36.4% and 38.5%, respectively. The relationships between the amount of atrazine adsorbed by soil colloids and corresponding atrazine concentrations in soil solutions may be described through the traditional and time-dependent desorption isotherms. The obvious discrepancies in two families of both traditional and time-dependent desorption isotherms from adsorption isotherm, which retention time last for 168 hours before commencement of desorption, were indicative of hysteresis. Two sets of Freundlich parameters derived from both desorption isotherms can quantify the hysteresis between desorption and adsorption isotherms. However, hysteresis coefficient, omega, was applicable only for the traditional desorption isotherms, H and lamda applicable for both.

[Adsorption of Cd and Pb on clays and the influence of humic acids].

Adsorption of cadmium and lead on montmorillonite and kaolin, together with the effect of humic substances was studied. It was found that adsorption amount of Cd and Pb increased as pH value of ambient solution increased. Addition of FA reduced Cd sorption on kaolin at each respective pH value while GHA and BHA increased Cd adsorption amount. A sharp increase was found at pH values higher than 6. Whereas, lead sorption on both clays in the presence of FA unexpectedly decreased as pH values increased when pH > 6.

[Effect of acetic acid on adsorption of acid phosphatase by some soil colloids and clay minerals].

This paper studied the effect of acetic acid with different concentrations and pH values on the adsorption of acid phosphatase by some soil colloids and clay minerals (SCCM). The results showed that the pH values for the maximum adsorption of the enzyme were between the IEP of the enzyme and the PZC of SCCM. In the acetic acid systems, the amount of the enzyme adsorbed by SCCM was in the order of goethite >> yellow brown soil > latosol > kaolinite > delta-MnO2. A remarkable influence of acetic acid concentration on the adsorption amount and the binding energy of the enzyme was observed. With the increase of the concentration from 0 to 200 mmol.L-1 in the system, acetic acid exhibited an enhanced effect, followed by an inhibition action on the adsorption of the enzyme on SCCM. The changes of the binding energy (K value) for the enzyme on SCCM were on the contrary to those of the maximum adsorption. The possible mechanisms for the influence of acetic acid on the adsorption of enzyme by SCCM were also discussed.

[Therapeutic effect of infrared radiation on skin scald in rats].

OBJECTIVE: To investigate the therapeutic effect of infrared radiation (IR) on the skin scald in rats. METHODS: Thirty-nine male Wistar rats were used in the study, and they were randomly divided into normal control (C, n = 13), scald (S, n = 13, no treatment after scalding) and treatment (T, n = 13, with IR radiation treatment for 5 days since 2nd post scalding day (PSD) groups. The rats in S and T groups were subjected to deep partial thickness scalding on the back. The cutaneous tissue samples from rat wound in each group were harvested on the 3rd and 7th PSD for pathomorphological examination. DNA synthesis in wound tissue was analyzed by 3H-TdR incorporation method, and the vascular permeability in cutaneous tissue, degree of tissue edema and MDA content were determined by corresponding methods. RESULTS: Epidermal exfoliation, cutaneous ulcer, follicular atrophy and damage, and massive formation of collagen were identified in the skin wound of rats in S group on the 7th PSD compared with C group. The skin in T group was smooth with slight atrophy and a few collagen fibers in follicles. The 3H-TdR incorporation amount in the rats in T group (1856.33 +/- 343.81 cpm/mg) on the 7th PSD was significantly higher than that in S group (1353.95 +/- 274.48 cpm/mg) (P < 0.01). The tissue permeability, edema degree and MDA content in the cutaneous tissue in S group were obviously higher than those in group C, while these indices were markedly lower in T group when compared with those in S group (P < 0.01-0.001). CONCLUSION: Treatment with IR seemed to be beneficial to the promotion of skin tissue metabolism and tissue repair.