The effectiveness of instrument-assisted soft tissue mobilization on range of motion: a meta-analysis.

BACKGROUND: To evaluate the effectiveness of instrument-assisted soft tissue mobilization (IASTM) on range of motion (ROM). METHODS: We performed a literature search of the PubMed, Embase, Web of Science, and Cochrane Library databases from inception to December 23, 2023. Randomized controlled trials that compared treatment groups receiving IASTM to controls or IASTM plus another treatment(s) to other treatment(s) among healthy individuals with or without ROM deficits, or patients with musculoskeletal disorders were included. The Cochrane risk of bias tool was used to assess the risk of bias. RESULTS: Nine trials including 450 participants were included in the quantitative analysis. The IASTM was effective in improving ROM in degree in healthy individuals with ROM deficits and patients with musculoskeletal disorders (n=4) (MD = 4.94, 95% CI: 3.29 to 6.60), and in healthy individuals without ROM deficits (n=4) (MD = 2.32, 95% CI: 1.30 to 3.34), but failed to improve ROM in centimeter in healthy individuals with ROM deficits (n=1) (MD = 0.39, 95% CI: -1.34 to 2.11, p=0.66, I2 = 88%). CONCLUSIONS: IASTM can improve ROM in degree in healthy individuals with or without ROM deficits, or in patients with musculoskeletal disorders (with very low to low certainty). TRIAL REGISTRATION: The PROSPERO registration ID is CRD42023425200.

Development and Validation Nomogram for Predicting the Survival of Patients with Thrombocytopenia in Intensive Care Units.

Background: The number of patients with thrombocytopenia (TCP) is relatively high in intensive care units (ICUs). It is therefore necessary to evaluate the prognostic risk of such patients. Aim: This study investigated the risk factors affecting the survival of patients with TCP in the ICU. Using the findings of this investigation, we developed and validated a risk prediction model. Methods: We evaluated patients admitted to the ICU who presented with TCP. We used LASSO regression to identify important clinical indicators. Based on these indicators, we developed a prediction model complete with a nomogram for the development cohort set. We then evaluated the mode's accuracy using a receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA) in a validation cohort. Results: A total of 141 cases of ICU TCP were included in the sample, of which 47 involved death of the patient. Clinical results were as follows: N (HR 0.91, 95% CI 0.86-0.97, P=0.003); TBIL (HR 1.98, 95% CI 1.02-1.99, P=0.048); APACHE II (HR 1.94, 95% CI 1.39, 2.48, P=0.045); WPRN (HR 6.22, 95% CI 2.86-13.53, P<0.001); WTOST (HR 0.56, 95% CI 0.21-1.46, P<0.001); and DMV [HR1.87, 95% CI 1.12-2.33]. The prediction model yielded an area under the curve (AUC) of 0.918 (95% CI 0.863-0.974) in the development cohort and 0.926 (95% CI 0.849-0.994) in the validation cohort. Application of the nomogram in the validation cohort gave good discrimination (C-index 0.853, 95% CI 0.810-0.922) and good calibration. DCA indicated that the nomogram was clinically useful. Conclusion: The individualized nomogram developed through our analysis demonstrated effective prognostic prediction for patients with TCP in ICUs. Use of this prediction metric may reduce TCP-related morbidity and mortality in ICUs.

Establishment of risk nomogram prediction model for venous catheter thrombosis.

BACKGROUND: Venous catheters are widely used in clinical practice, but a drawback of their usage is the increased risk of thrombosis. AIMS: The current study explored the risk factors affecting the formation of thrombosis following venous catheterization and establishes a risk nomogram prediction model for catheter-related thrombosis. METHODS: Univariate and multivariate logistic regression analyses were carried out to identify the independent factors involved in venous catheter thrombosis. These factors were included in the construction of a nomogram. Finally, the C-index and calibration curves were used to validate the nomogram. RESULT: A total of 146 cases were included in the sample, of which 36 were cases of thrombosis. The results of the univariate logistic regression analysis showed that the following were significant factors: age, Acute Physiology and Chronic Health Evaluation scoring system (APACHE II) score, white blood cell (WBC), hematocrit (HCT), international normalized ratio (INR), fibrinogen (FIB), and D-dimer. Multivariate logistic regression analysis was performed, which confirmed that the factors of age (AUC: 0.677, 95% CI: 0.564-0.790), APACHE II score (AUC: 0.746, 95% CI: 0.656-0.837), INR (AUC: 0.743, 95% CI: 0.636-0.849), and D-dimer (AUC: 0.826, 95% CI: 0.750-0.902) were independent variables. Next, a nomogram was constructed using these independent variables for predicting venous catheter thrombosis. Favorable results with C-indexes (0.816; 95% CI: 0.780-0.882) and calibration curves closer to ideal curves indicated the accurate predictive ability of this nomogram. CONCLUSION: The individualized nomogram demonstrated effective prognostic prediction for patients with venous thrombosis.

Erratum to: Developmental recording of the ghost-moth larvae after ex situ infection by Ophiocordyceps sinensis.

This paper contains errors in the authors' affiliations. Wenjia Li, is a Ph.D. candidate in the University of Chinese Academy of Sciences, Jiangchun Wei and Xingzhong Liu are professors in the University of Chinese Academy of Sciences, which is missing in the original version. The affiliations have been corrected.

Idebenone reduces sepsis-induced oxidative stress and apoptosis in hepatocytes via RAGE/p38 signaling.

Background: Sepsis-induced liver dysfunction is believed to be an independent risk factor for multiple organ dysfunction and death. Idebenone (IDE), a synthetic analog of coenzyme Q10 (CoQ10), possesses an antioxidizing property. The present study aimed to investigate the efficacy of IDE on sepsis-induced liver injury and discuss its reaction mechanism in vivo and in vitro. Methods: To establish an in vivo model of sepsis-induced liver injury, rats were treated with high-grade cecal ligation and puncture (CLP). Hematoxylin-eosin staining was applied to observe the liver pathological changes, and liver function was examined using alanine aminotransferase (ALT) and aspartate aminotransferase (AST) assay kits. Enzyme-linked immunosorbent assay (ELISA) kits were employed to assess the levels of inflammatory cytokines in serum and tissues. The activities of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were analyzed using MDA, SOD, and GSH-Px assay kits, respectively. The apoptosis of liver tissues was measured by terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) staining, and western blot was employed to estimate apoptosis-related proteins. In vitro, 0.5 µg/mL lipopolysaccharide (LPS) was adopted to administrate primary hepatocytes. The expressions of receptor for advanced glycation end products (RAGE)/p38-related proteins were evaluated by western blot. Cell counting kit-8 (CCK-8) and dichloro-dihydro-fluorescein diacetate (DCFH-DA) assays were utilized to estimate cell viability and reactive oxygen species (ROS) content. Moreover, the transfection efficacy of overexpression (Ov)-RAGE in primary hepatocytes was tested by real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. Results: IDE could improve liver function and reduce sepsis-induced pathological damage. The levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) in the serum and liver tissue of sepsis rats were suppressed by IDE. Additionally, IDE repressed the oxidative stress and apoptosis of liver tissues in sepsis-induced rats. IDE also inhibited RAGE/p38 signaling. Furthermore, IDE revived the decreased viability in LPS-induced hepatocytes concentration-dependently. After overexpressing RAGE, RAGE expression in hepatocytes was significantly elevated. Further functional experiments revealed that IDE attenuated cell viability injury, apoptosis, oxidative stress, and inflammatory damage in LPS-induced hepatocytes via RAGE/p38 signaling. Conclusions: IDE helped to protect against sepsis-induced liver injury via the regulation of RAGE/p38 signaling.

Differentiation of white architectural paints by microscopic laser Raman spectroscopy and chemometrics.

A feasible, effective and non-destructive method that could be used to differentiate architectural paints was proposed by Microscopic laser Raman spectroscopy and chemometrics. A total of 252 white architectural paints from 7 different manufacturers were prepared for evaluating the potential of differentiating them. 5th Newton interpolation polynomial combined with Savitzky-Golay 7-point and 1st or 2nd polynomial smoothing under the 1st-order derivative were considered as the optimal pre-processing method for MLRM data. The Bayes discriminant analysis model realized 100% accuracy based on discriminant functions Z1, Z2 and Z3, which was the more useful and practical method for differentiating white architectural paints than that of multilayer perceptron and radial basis function neural network models. All samples were differentiated exactly, which was rapid and non-destructive. The designed method demonstrated the potential of Microscopic Laser Raman spectroscopy in combination with pre-processing and chemometrics as a universal, confirmatory, and accurate method for the white architectural paint differentiation in forensic science.

Early use of high-dose vitamin C is beneficial in treatment of sepsis.

PURPOSE: Vitamin C has shown benefits in patients with sepsis in addition to standard therapy recently. However, further evidence is required to verify the efficacy of vitamin C in clinical practice. This study aimed to investigate the effect of adjunctive intravenous high-dose vitamin C treatment on hospital mortality in patients with sepsis. METHODS: One hundred seventeen patients with sepsis in our department from June 2017 to May 2019 were randomly divided into two groups: the control group (56 cases) and the vitamin C group (61 cases). The control group was treated by the routine and basic therapy with intravenous drip of 5% dextrose and placebo (100 ml/time, 2 times/day), while the vitamin C group was administered intravenously by 3.0 g vitamin C dissolved into 5% dextrose (100 ml/time, 2 times/day) based on the control group. The mortality and efficacy were statistically analyzed and compared between the two groups. RESULTS: The 28-day mortality differed significantly between the control group and the vitamin C group (42.97% vs. 27.93%) (p < 0.05). The changes in the sepsis-related organ failure assessment (ΔSOFA) scores at 72 h after ICU admission (4.2 vs. 2.1), the application time of vasoactive drugs (25.6 vs. 43.8), and the procalcitonin clearance (79.6% vs. 61.3%) differed significantly between groups (p < 0.05). CONCLUSION: The early treatment of sepsis with intravenous high-dose vitamin C in combination with standard therapy showed a beneficial effect on sepsis, in terms of the reduced 28-day mortality, the decreased SOFA score, and the increased clearance rate of procalcitonin.

[On the Tributylphosphate-Based Super-Concentrated HCl System].

We reported a new super-concentrated hydrochloric acid system prepared by using tri-n-butyl phosphate (TBP)-constructed reversed micelles at ambient temperature and pressure. According to the titration result, the molar ratio of H+ to H2O (denoted as nH+/nH2O) in the super-concentrated HCl range from 0.50 to 1.50 which are higher than that in saturated aqueous HCl bulk solution (0.28). Significant a moment of hydrochloric acid is confined in W/O reversed micelles. Therefore, the behavior and status of HCl are different from those of conventional bluk solution. FTIR spectroscopic results demonstrate that a significant amount of HCl remains in the molecular form rather than being ionized into H+ and Cl-. Thus, super-concentrated HCl provides an extraordinary chemical environment which may have significant influence on certain substances. We found that the color of the solution is reddish brown when copper ion is dissolved in super-concentrated HCl, while the color of the saturated HCl aqueous solution (37 Wt%) containing copper ion is green. That is to say, the copper ions exist in a special state under the unique chemical environment of super-concentrated HCl. UV-Vis-NIR spectra indicate that both d-d transition band and charge transfer transition band of copper ions in super-concentrated HCl solution underwent significant variations. In addition, copper ions also have obvious influence on the hydrogen bond network among HCl in the super-concentrated HCl solution. Remarkable variation is introduced in the H-Cl stretching band in FTIR spectra.

[The effect of paraquat on voltage-dependent anion channel and caspase-3, 8, 9 in the mitochondria of rat lung].

OBJECTIVE: To investigate the effects of different concentrations of paraquat (PQ) poisoning on the expression of voltage-dependent anion channel (VDAC) and caspase family in the mitochondria of rat lung tissue, and to explore possible mechanisms of acute lung injury induced by acute PQ poisoning. METHODS: Two hundred healthy adult Wister rats with equal numbers of male and female ones were randomly and equally divided into control group and poisoned group. The control group received one-time gastric lavage with 1 ml of normal saline, and the poisoned group with PQ (50 mg/kg) diluted in 1 ml of normal saline. Twenty rats were collected at 1, 24, 72, 120, and 168 h after lavage with normal saline or PQ and dissected after anesthesia. Mitochondria were separated from rat lung tissue, and the content of VDAC and caspase-3, -8, and -9 were determined. RESULTS: The expression of VDAC and caspase-3, -8, and -9 in the poisoned rats were significantly higher than that in the control group (P < 0.001). At 1, 24, 72, 120, and 168 h after exposure, acute diffuse damages were found in alveolar capillary endothelial cells, alveolar epithelial cells, and pulmonary interstitial cells. Inflammatory cell infiltration in the pulmonary interstitium, alveolar structural disorder, and substantially increased fibroblasts were also found in rat lung tissue. CONCLUSION: PQ poisoning can up-regulate the expression of VDAC and caspase-3, -8, and -9 in mitochondria of rat lung tissue to induce acute lung injury.

[Influence of Concentration Sequence on the Signal-to-Noise Ratio of Cross Peaks of 2D Asynchronous Spectra Generated by Using the DAOSD Approach].

In the present work, computer simulation was performed on a model chemical system where two solutes (denoted as P and Q, respectively) are dissolved in the same solution. Under intermolecular interaction between P and Q, part of P undergoes subtle structural variation and converts into U while part of Q converts into V. The strength of intermolecular interaction can be characterized by the corresponding equilibrium constant K. Our preliminary studies indicate that the S/N ratio of cross peak increases considerably as n increases. Moreover, the S/N ratio of the cross peak from the asynchronous spectra can be improved significantly when the suitable concentrations of P and Q are adopted. This work is helpful for a selection of suitable concentration sequence to maximize S/N ratio of cross peaks in the 2D asynchronous spectra generated by using the DAOSD approach proposed in our previous study so that weak intermolecular interaction can be probed.

An anti-H5N1 influenza virus FcDART antibody is a highly efficacious therapeutic agent and prophylactic against H5N1 influenza virus infection.

UNLABELLED: Highly pathogenic H5N1 avian influenza viruses are associated with severe disease in humans and continue to be a pandemic threat. While vaccines are available, other approaches are required for patients that typically respond poorly to vaccination, such as the elderly and the immunocompromised. To produce a therapeutic agent that is highly efficacious at low doses and is broadly specific against antigenically drifted H5N1 influenza viruses, we developed two neutralizing monoclonal antibodies and combined them into a single bispecific Fc fusion protein (the Fc dual-affinity retargeting [FcDART] molecule). In mice, a single therapeutic or prophylactic dose of either monoclonal antibody at 2.5 mg/kg of body weight provided 100% protection against challenge with A/Vietnam/1203/04 (H5N1) or the antigenically drifted strain A/Whooper swan/Mongolia/244/05 (H5N1). In ferrets, a single 1-mg/kg prophylactic dose provided 100% protection against A/Vietnam/1203/04 challenge. FcDART was also effective, as a single 2.5-mg/kg therapeutic or prophylactic dose in mice provided 100% protection against A/Vietnam/1203/04 challenge. Antibodies bound to conformational epitopes in antigenic sites on the globular head of the hemagglutinin protein, on the basis of analysis of mutants with antibody escape mutations. While it was possible to generate escape mutants in vitro, they were neutralized by the antibodies in vivo, as mice infected with escape mutants were 100% protected after only a single therapeutic dose of the antibody used to generate the escape mutant in vitro. In summary, we have combined the antigen specificities of two highly efficacious anti-H5N1 influenza virus antibodies into a bispecific FcDART molecule, which represents a strategy to produce broadly neutralizing antibodies that are effective against antigenically diverse influenza viruses. IMPORTANCE: Highly pathogenic H5N1 avian influenza viruses are associated with severe disease in humans and are a pandemic threat. A vaccine is available, but other approaches are required for patients that typically respond poorly to vaccination, such as the elderly and the immunocompromised. The variability of the virus means that such an approach must be broad spectrum. To achieve this, we developed two antibodies that neutralize H5N1 influenza viruses. In mice, these antibodies provided complete protection against a spectrum of H5N1 influenza viruses at a single low dose. We then combined the two antibodies into a single molecule, FcDART, which combined the broad-spectrum activity and protective efficacy of both antibodies. This treatment provides a novel and effective therapeutic agent or prophylactic with activity against highly pathogenic H5N1 avian influenza viruses.

[Studies on carbonization of saccharides by using aqueous solution of various acids].

The authors tried to establish an approach to use acids to convert biomass into a fuel with higher carbon content and lower oxygen content in a zero-energy-consumption fashion. Considering that biomass is composed of monosaccharide, we used aqueous solutions of variation acids including hydrochloric acid, sulfuric acid and perchloric acid to treat 2-deoxy-ribose and fructose at ambient temperature and pressure. Black substances were produced after a period of time when 2-deoxy-ribose and fructose were mixed with aqueous solutions containing 8 mol · L(-1) acids. The black substance was collected and characterized by using elemental analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Elemental analysis results indicate that the contents of carbon increases significantly in the black substances in comparison with 2-deoxy-ribose and fructose. Moreover, XPS results indicate that the content of oxygen in the black substance undergoes a significant decrease compared with pure 2-deoxy-ribose and fructose. In the XPS spectra, the is peaks of 2-deoxy-ribose, strong sub peak at 286. 05 eV, which is assigned to carbon linked to oxygen directly, dominate in the C is peak envelop. After treatment by HClO4, the peak decreased dramatically. This result also supports the conclusion that the content of oxygen in mono-saccharide is significantly reduced after treatment by acids. In the FTIR spectra of the black substances, strong peaks can be observed around 1 600 cm(-1), indicating that C==C bond is formed in the product. The above results suggest that treatments with acids may be developed as a new zero-energy-consumption approach to convert biomass in a new fuel with improved energy output efficiency.

A comparison of bilevel and continuous positive airway pressure noninvasive ventilation in acute cardiogenic pulmonary edema.

BACKGROUND: Whether bilevel positive airway pressure (BiPAP) is advantageous compared with continuous positive airway pressure (CPAP) in acute cardiogenic pulmonary edema (ACPO) remains uncertain. The aim of the meta-analysis was to assess potential beneficial and adverse effects of CPAP compared with BiPAP in patients with ACPO. METHODS: Randomized controlled trials comparing the treatment effects of BiPAP with CPAP were identified from electronic databases and reference lists from January 1966 to December 2012. Two reviewers independently assessed study quality. In trials that fulfilled inclusion criteria, we critically evaluate the evidence for the use of noninvasive ventilation on rates of hospital mortality, endotracheal intubation, myocardial infarction, and the length of hospital stay. Data were combined using Review Manager 4.3 (The Cochrane Collaboration, Oxford, UK). Both pooled effects and 95% confidence intervals (CIs) were calculated. RESULTS: Twelve randomized controlled trials with a total of 1433 patients with ACPO were included. The hospital mortality (relative risk [RR], 0.86; 95% CI, 0.65-1.14; P = .46; I(2) = 0%) and need for requiring invasive ventilation (RR, 0.89; 95% CI, 0.57-1.38; P = .64; I(2) = 0%) were not significantly different between patients treated with CPAP and those treated with BiPAP. The occurrence of new cases of myocardial infarction (RR, 0.95; 95% CI, 0.77-1.17; P = .53, I(2) = 0%) and length of hospital stay (RR, 1.01; 95% CI, -0.40 to 2.41; P = .98; I(2) = 0%) were also not significantly different between the 2 groups. CONCLUSIONS: There are no significant differences in clinical outcomes when comparing CPAP vs BiPAP. Based on the limited data available, our results suggest that there are no significant differences in clinical outcomes when comparing CPAP with BiPAP.

Cooperativity in virus neutralization by human monoclonal antibodies to two adjacent regions located at the amino terminus of hepatitis C virus E2 glycoprotein.

A challenge for hepatitis C virus (HCV) vaccine development is defining conserved epitopes that induce protective antibodies against this highly diverse virus. An envelope glycoprotein (E2) segment located at amino acids (aa) 412 to 423 contains highly conserved neutralizing epitopes. While polyclonal antibodies to aa 412 to 423 from HCV-infected individuals confirmed broad neutralization, conflicting findings have been reported on polyclonal antibodies to an adjacent region, aa 434 to 446, that may or may not interfere with neutralization by antibodies to aa 412 to 423. To define the interplay between these antibodies, we isolated human monoclonal antibodies (HMAbs) to aa 412 to 423, designated HC33-related HMAbs (HC33 HMAbs), and characterized their interactions with other HMAbs to aa 434 to 446. A subset of the HC33 HMAbs neutralized genotype 1 to 6 infectious cell culture-derived HCV virions (HCVcc) with various activities. Although nonneutralizing HC33 HMAbs were isolated, they had lower binding affinities than neutralizing HC33 HMAbs. These antibodies could be converted to neutralizing antibodies by affinity maturation. Unidirectional competition for binding to E2 was observed between HC33 HMAbs and HMAbs to aa 434 to 446. When HMAbs to aa 434 to 446, which mediated neutralization, were combined with neutralizing HC33 HMAbs, biphasic patterns in neutralization were observed. A modest degree of antagonism was observed at lower concentrations, and a modest degree of synergism was observed at higher concentrations. However, the overall effect was additive neutralization. A similar pattern was observed when these antibodies were combined to block E2 binding to the HCV coreceptor, CD81. These findings demonstrate that both of these E2 regions participate in epitopes mediating virus neutralization and that the antibodies to aa 412 to 423 and aa 434 to 446 do not hinder their respective virus-neutralizing activities.

[The analysis for silver iodide fine particles of TLC/FTIR matrix].

In situ TLC/FTIR technique has tremendous potential in the analysis of complex mixtures. However, the progress in this technique was quite slow. The reason is that conventional stationary phase has strong absorption in FTIR spectrum and thus brings about severe interference in the detection of samples. To solve the problem, the authors propose to use AgI fine particles as stationary phase of TLC plate. The reasons are as follows: Silver iodide fine particles have no absorbance in an IR region between 4 000 and 800 cm(-1), therefore, the interference caused by IR absorption of stationary phase can be removed. Moreover, silver iodide is stable and insolvable in water and organic solvents and thus it will not be destroyed by mobile phase or react with samples during the TLC separation. To improve TLC separation efficiency and quality of FTIR spectra during the TLC/FTIR analysis, the size of AgI particles should be below 500 nm. We used orthogonal design approach to optimize the experimental condition to AgI particles so that the average size of AgI particles is around 100 nm. No absorption of impurity or adsorbed water were observed in FTIR spectrum of the AgI particles the authors used "settlement volatilization method" to prepare TLC plate without using polymeric adhesive that may bring about significant interference in FTIR analysis. Preliminary TLC experiments proved that the TLC plate using AgI fine particles as stationary phase can separate mixtures of rhodamine B and bromophenol blue successfully. Applications of silver iodide fine particles as stationary phase have bright perspective in the development of in-situ TLC/FTIR analysis techniques.

[Investigation of thermal behaviors of γ-form nylon 6 prepared by ammonia vapor from phosphoric acid solutions].

In the present work, we prepared nylon 6 crystals via crystallization of nylon from phosphoric acid by using the vapors of ammonium hydroxide as a precipitation regent. Both XRD and FTIR results demonstrate that the obtained nylon 6 sample exhibit characteristic peaks of nylon 6 in gamma form. In addition, treatment of nylon 6 in boiling water for half an hour followed by FTIR and XRD characterization shows that the obtained nylon 6 sample is in gamma form rather than in meta-stable b form. DSC characterization indicates that the nylon 6 sample exhibits two melting peaks (213 and 220 degrees C) when the sample is heated at a heating rate of 10 degrees C x min(-1). The reason for this phenomenon is that the nylon 6 sample has different lamellar thickness. To investigate the thermal behavior of the nylon 6 sample, the sample underwent the following thermal treatment procedure. First, the sample was heated to a pre-set temperature (T(s)) and kept at that temperature for an hour. Subsequently, the sample was cooled down to 100 degrees C at a cooling rate of 1 degrees C x min(-1), and then cooled down to room temperature at a cooling rate of 10 degrees C x min(-1). The treated samples were characterized by FTIR and DSC method. Experimental results show that the treated nylon 6 samples exhibit different crystalline behavior. When T. ranges from 130 to 160 degrees C, no significant changes were observed. When T(s) is 170 degrees C, a small fraction nylon 6 crystals is destroyed and recrystallized into thin lamellae in a form. As a result, a pre-melting peak appears in DSC result. The pre-melting peak moves to higher temperature and its peak area increases significantly upon increasing T(s) from 170 to 198 degrees C. When T(s) amounts to 200 degrees C, the pre-melting peak and the melting peaks 213 degrees C merge into one melting peak and two melting peaks are observed at 212 and 220 degrees C in the DSC results. FTIR spectra indicate that significant amount of crystalline nylon 6 in a form appears but the majority of crystalline phase of the sample is still gamma phase. As T(s) increases from 200 to 209 degrees C, the melting peak at lower temperature moves to higher temperature with increasing its peak area. On the other hand, the melting peak at 220 degrees C decreases in intensity but does not show any peak shift. As T(s) reaches 209 degrees C, the two melting peaks merge into one peak and FTIR results demonstrate that nylon 6 in a form becomes dominate phase in the sample. In the whole heat-treatment process, the gamma phase nylon 6 sample began to transform to a phase at the heat-treatment temperature of 170 degrees C, which is far below the melting point of the original sample (221 degrees C). This is different from the results reported in the literature, which state that gamma phase nylon 6 will not transform to alpha-phase until nylon is melt.

Adsorption properties and degradation dynamics of endocrine-disrupting chemical levonorgestrel in soils.

Levonorgestrel, a synthetic progesterone used as an oral contraceptive or emergency contraceptive pill, has been shown to be an endocrine-disrupting chemical. To assess the environmental risk of levonorgestrel, batch experiments and laboratory microcosm studies were conducted to investigate the adsorption and degradation of levonorgestrel in five contrasting soils of China. Freundlich and Langmuir models were applied to sorption data to examine the affinity of levonorgestrel for soils with varying physical and chemical properties. The K(f) of levonorgestrel in the tested soils ranged from 10.79 to 60.92 mg(1-n) L(n) kg(-1) with N between 0.69 and 1.23, and the Q(m) ranged from 18.18 to 196.08 mg/kg. The multiple regression analysis was conducted between K(f) and soil properties. Results indicate that total organic carbon plays a dominant role in the adsorption process. Gibbs free energy values less than 40 kJ/mol demonstrate that levonorgestrel sorption on soils could be considered as a physical adsorption. The degradation of levonorgestrel in five soils was fitted by the first-order reaction kinetics model. The half-lives of levonorgestrel were between 4.32 and 11.55 days. The initial concentration and sterilization experiments illustrated that the degradation rate of levonorgestrel in soil was concentration-dependent and microbially mediated. The low mobility potential of levonorgestrel in soils was predicted by the groundwater ubiquity score (GUS) and retardation factor (R(f)).