Naturally Derived Injectable Dual-Cross-Linked Adhesive Hydrogel for Acute Hemorrhage Control and Wound Healing.

Developing biocompatible injectable hydrogels with high mechanical strength and rapid strong tissue adhesion for hemostatic sealing of uncontrolled bleeding remains a prevailing challenge. Herein, we engineer an injectable and photo-cross-linkable hydrogel based on naturally derived gelatin methacrylate (GelMA) and N-hydroxysuccinimide-modified poly(γ-glutamic acid) (γPGA-NHS). The chemically dual-cross-linked hydrogel rapidly forms after UV light irradiation and covalently bonds to the underlying tissue to provide robust adhesion. We demonstrate a significantly improved hemostatic efficacy of the hydrogel using various injury models in rats compared to the commercially available fibrin glue. Notably, the hydrogel can achieve hemostasis in porcine liver and spleen incision, and femoral artery puncture models. Moreover, the hydrogel is used for sutureless repair of the liver defect in a rat model with a significantly suppressed inflammatory response, enhanced angiogenesis, and superior healing efficacy compared to fibrin glue. Together, this study offers a promising bioadhesive for treating severe bleeding and facilitating wound repair.

Observation on efficacy and underlying mechanism of cheek acupuncture on ovulation induction for infertile women with PCOS: Case series.

RATIONALE: Polycystic ovary syndrome (PCOS) is the most common reproductive endocrine disorder among women of childbearing age and is the primary cause of anovulatory infertility, accounting for 70% to 80% of cases. Ovulation induction is the main treatment approach for infertile patients with PCOS. Commonly utilized medications for this purpose are clomiphene citrate (CC) and letrozole (LE). Clomiphene citrate administration results in an ovulation rate ranging from 60% to 85%, while the pregnancy rate is limited to 35% to 40%, and a further reduction is observed in live birth rates. Letrozole demonstrates a slightly higher pregnancy rate and live birth rate compared to clomiphene citrate, although challenges persist in terms of longer stimulation cycles, multiple pregnancies, and the risk of ovarian hyperstimulation syndrome (OHSS). Clinical reports indicate that acupuncture therapy shows promising efficacy in treating patients with PCOS-related infertility, despite a partially unclear understanding of its underlying mechanisms. PATIENT CONCERNS: In this study, one patient did not achieve pregnancy despite more than a year of ovulation induction using clomiphene citrate and letrozole. However, after 3 months of receiving cheek acupuncture therapy, she successfully conceived and gave birth to a liveborn baby. Another patient achieved natural conception and live birth after 2 months of exclusive cheek acupuncture therapy. DIAGNOSIS: PCOS. INTERVENTIONS: Cheek acupuncture therapy. OUTCOMES: Both of them successfully conceived and gave birth to a liveborn baby. LESSONS: These findings suggest that cheek acupuncture therapy can effectively stimulate follicle development and ovulation, potentially improving endometrial receptivity. According to holographic theory, there is a biologically holographic model within the cheek region that shares a homology with the human body structure. This model provides an explanation for the regulatory effects of cheek acupuncture point stimulation on the Hypothalamic-Pituitary-Ovarian axis (HPO), which subsequently influences follicle development and ovulation in patients. Consequently, when cheek acupuncture therapy is applied alone or in combination with ovulation induction medication, patients have the ability to achieve successful pregnancy and experience a smooth delivery.

Disentangling sources and transformation mechanisms of nitrogen, sulfate, and carbon in water of a Karst Critical Zone.

In the Karst Critical Zone (KCZ), mining and urbanization activities produce multiple pollutants, posing a threat to the vital groundwater and surface water resources essential for drinking and irrigation. Despite their importance, the interactions between these pollutants in the intricate hydrology and land use of the KCZ remain poorly understood. In this study, we unraveled the transformation mechanisms and sources of nitrogen, sulfate, and carbon using multiple isotopes and the MixSIAR model, following hydrology and surface analyses conducted in spatial modelling with ArcGIS. Our results revealed frequent exchange between groundwater and surface water, as evidenced by the analysis of δD-H2O and δ18O-H2O. Nitrification predominantly occurred in surface water, although denitrification also made a minor contribution. Inorganic nitrogen in both groundwater and surface water primarily originated from soil nitrogen (48 % and 49 %, respectively). Sewage and manure were secondary sources of inorganic nitrogen in surface water, accounting for 41 % in urban and 38 % in mining areas. Notably, inorganic sulfur oxidation displayed significant spatial disparities between urban and mining areas, rendering groundwater more susceptible to sulfur pollution compared to surface water. The frequent interchange between groundwater and surface water posed a higher pollution risk to groundwater. Furthermore, the primary sources of CO2 and HCO3- in both groundwater and surface water were water­carbonate reactions and soil respiration. Sulfide oxidation was found to enhance carbonate dissolution, leading to increased CO2 release from carbonate dissolution in the KCZ. These findings enhance our understanding of the transformation mechanisms and interactions of nitrogen, sulfur, and carbon in groundwater and surface water. This knowledge is invaluable for accurately controlling and treating water pollution in the KCZ.

Treatment of lactational mastitis with Gualou Xiaoyong soup and painless lactation promoting technique: A case series.

BACKGROUND: Lactational mastitis is a common and frequently disease in clinical practice, characterized by acute inflammation of the mammary ducts and surrounding connective tissues. The main manifestations are damage to the mammary gland acini, edema, and invasion of inflammatory cells. If not treated properly, it may lead to the formation of breast abscesses, or even sepsis, septic shock, and chronic inflammation of the breast, which may cause the disease to persist or recur multiple times, so that the patients suffer extreme pain, and the health of both the mother and child are directly affected. This disease not only causes suffering for women but also may result in the cessation of breastfeeding. Therefore, rapid and effective treatment is particularly important. CASE SUMMARY: We report 3 cases of lactation mastitis patients showing good clinical efficacy after being treated with the Chinese medicine Gualou Xiaoyong soup and painless lactation promoting techniques. Gualou Xiaoyong soup combined with painless lactation promotion techniques can significantly reduce and eliminate the clinical symptoms of patients in the short term, and rapidly restore inflammatory indicators such as total white blood cells, neutrophils, C-reactive protein, and procalcitonin to normal levels. The patchy low echo area of the breast under B-ultrasound also disappears quickly. Therefore, we believe that this method is a good way to treat lactational mastitis and is worthy of clinical reference and research. However, this study has certain limitations: this study lacks a large sample of prospective controlled studies. Next, we will continue to collect relevant cases and conduct prospective case randomized controlled clinical studies. CONCLUSION: The treatment of lactation mastitis with Gualou Xiaoyong soup and painless lactation promoting techniques can achieve good clinical results.

Sanji Peiyuan decoction combined with dydrogesterone in the treatment of massive subchorionic hematoma: A case report.

RATIONALE: Subchorionic Hematoma, often referred to as Bruce hematoma, can lead to serious obstetric complications such as intrauterine growth restriction and fetal death, as well as early and late pregnancy miscarriage, placental abruption, and premature rupture of membranes, posing great harm to both mother and fetus. PATIENT CONCERNS: At present, Western medical treatments have not shown satisfactory results, necessitating the discovery of more effective clinical treatment methods. DIAGNOSES: Threatened miscarriage, Subchorionic hematoma, Iron deficiency anemia (mild). INTERVENTIONS: Sanji Peiyuan decoction combined with dydrogesterone. OUTCOMES: Following 17 days of treatment with Sanji Peiyuan decoction and oral dydrogesterone tablets, the hematoma was no longer detectable by ultrasound. The patient experienced no symptoms such as abdominal pain, bloating, or vaginal bleeding. She successfully gave birth around her due date, with both the mother and child in good health. LESSONS: The combination of Sanji Peiyuan decoction and oral dydrogesterone tablets shows promising clinical efficacy in treating Massive Subchorionic Hematomas. This method merits further clinical research.

Clinical efficacy of Gualou Xiaoyong Decoction and painless lactation manipulation in treating lactation acute mastitis and breast abscess: An observational study.

Information on the effects of Chinese medicine in the treatment of lactational acute mastitis and breast abscess is limited; thus, we conducted an observational study to analyze the clinical efficacy of Gualou Xiaoyong Decoction combined with painless lactation manipulation in the treatment of lactational acute mastitis and breast abscess. A total of 41 patients with lactational acute mastitis and breast abscess who were treated with Gualou Xiaoyong Decoction and painless lactation manipulation from October 2021 to October 2022 were included in this study. The age, fetal times(primiparous/multiparous), delivery mode (cesarean section/vaginal delivery), onset time, breast lump diameter, skin rash diameter, body temperature, visual analogue score, blood routine, C-reactive protein, procalcitonin, bacterial culture in milk, B ultrasound and other data of these patients were statistically analyzed. After treatment, the breast lump diameter of these patients decreased significantly, the skin rash diameter was reduced or disappeared, the body temperature decreased or returned to a normal range, and the visual analogue score also decreased. Besides, these patients had a decreased total number of white blood cells and a reduced percentage of neutrophils, C-reactive protein, and procalcitonin after treatment. In addition, bacteria in the milk of most patients disappeared, and there was no abnormality in B ultrasonic imaging. Except for 2 patients with breast abscess who stopped breastfeeding on the affected side for 1 day and 3 days respectively, all other patients continued to provide breast milk for their infants, and no adverse reactions were observed in these infants. The combination of Gualou Xiaoyong Decoction and painless lactation manipulation can achieve favorable clinical effects in the treatment of lactational acute mastitis and breast abscess. This combined therapy has good efficacy, short course of treatment, low costs, and great convenience with the avoidance of pain, hospitalization, influence on lactation, breast scar and other adverse outcomes.

Sources and fates of particulate organic matter in inland waters with complex land use patterns.

Elucidating the sources of particulate organic matter (POM) is the foundation for understanding their fates and the seasonal variation of their movement from the land-to-ocean aquatic continuum (LOAC). The POM from different sources has different reactivity, which determines their fates. However, the key link between the sources and fates of POM, especially in the complex land use watersheds in bays is still unclear. Stable isotopes and contents of organic carbon and nitrogen were applied to reveal them in a complex land use watershed with different gross domestic production (GDP) in a typical Bay, China. Our results showed that the POMs preserved in suspended particulate organic matter (SPM) were weakly controlled by assimilation and decomposition in the main channels. Source apportionments of SPM in the rural area were controlled by soil (46 % ~ 80 %), especially inert soils eroded from land to water due to precipitation. The contribution of phytoplankton resulted from slower water velocity and longer residence time in the rural area. The soil (47 % ~ 78 %) and manure and sewage (10 % ~ 34 %) were the two major contributors to SOMs in the developed and developing urban areas. The manure and sewage were important sources of active POM in the urbanization of different LUI, which showed discrepancies in the three urban areas (10 % ~ 34 %). Due to soil erosion and the most intensive industry supported by GDP, the soil (45 % ~ 47 %) and industrial wastewater (24 % ~ 43 %) were the two major contributors to SOMs in the industrial urban area. This study demonstrated the close relationship between the sources and fates of POM with complex land use patterns, which could reduce uncertainties in future estimates of the LOAC fluxes and secure ecological and environmental barriers in a bay area.

Lactation breast abscess treated with Gualou Xiaoyong decoction and painless lactation manipulation: A case report and review of literature.

BACKGROUND: Breast abscess during lactation is a severe complication of acute mastitis, which can lead to discomfort, high fever, breast fistula, sepsis, septic shock, breast damage, disease persistence and frequent hospitalization. Breast abscesses may also lead the mother to discontinue breastfeeding, thereby harming the infant's health. The predominant pathogenic bacteria are Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus. The incidence of breastfeeding abscesses in breastfeeding women ranges between 4.0% and 11.0%. In cases of breast abscess, the rate of cessation of lactation is 41.0%. In instances of breast fistula, the rate of cessation of lactation is very high (66.7%). Furthermore, 50.0% of women with breast abscesses must be hospitalized and treated with intravenous antibiotics. Treatment includes antibiotics, abscess puncture and surgical incision and drainage. The patients suffer from stress, pain and easily induced breast scarring; the disease's progression is prolonged and recurrent, interfering with infant feeding. Consequently, it is crucial to discover an adequate cure. CASE SUMMARY: A 28-year-old woman with a breast abscess was treated with Gualou Xiaoyong decoction and painless breast opening manipulation 24 d after cesarean delivery. On the 2nd d of treatment, the patient's breast mass was significantly reduced, the pain was significantly reduced, and the general asthenia was improved. All conscious symptoms disappeared after 3 d, breast abscesses faded after 12 d of treatment, inflammation images disappeared after 27 d, and normal lactation images were restored. CONCLUSION: In treating breast abscesses during breastfeeding, the combination of Gualou Xiaoyong decoction and painless lactation provides a positive therapeutic impact. This disease's treatment offers the advantages of a short course of treatment, no need to discontinue breastfeeding and the ability to rapidly mitigate symptoms, which can be used as a reference in clinical practice.

In situ forming injectable γ-poly(glutamic acid)/PEG adhesive hydrogels for hemorrhage control.

Rapidly in situ forming adhesive hydrogels are promising candidates for efficient hemostasis due to their easy administration and minimal invasion. However, development of biocompatible and high-performance hemostatic hydrogels without any additional toxic agents remains a challenge. Herein, a series of novel injectable adhesive hydrogels based on N-hydroxysuccinimide (NHS) modified γ-poly(glutamic acid) (γPGA-NHS) and tetra-armed poly(ethylene glycol) amine (Tetra-PEG-NH2) were developed. Among all samples, PGA10-PEG15 and PGA10-PEG20 hydrogels with higher PEG contents exhibited rapid gelation time (<20 s), strong mechanical strength (compression modulus up to ∼75 kPa), good adhesive properties (∼15 kPa), and satisfactory burst pressure (∼18-20 kPa). As a result, PGA10-PEG15 and PGA10-PEG20 hydrogels showed a remarkable reduction in hemostasis time and blood loss compared with gauze and fibrin glue. More importantly, the PGA10-PEG20 hydrogel was also successfully used to seal femoral arterial trauma. Subcutaneous implantation experiments indicated a good biocompatibility of the hydrogels in vivo. All these results strongly support that the developed PGA-PEG hydrogels could serve as promising hemostatic agents in emergency and clinical situations.

Contribution of ammonia-oxidizing archaea and bacteria to nitrification under different biogeochemical factors in acidic soils.

Nitrification in soils is an essential process that involves archaeal and bacterial ammonia-oxidizers. Despite its importance, the relative contributions of soil factors to the abundance of ammonia-oxidizing archaea (AOA) and bacteria (AOB) and their nitrification performances are seldom discussed. The aim of this study was to determine the effects of AOA and AOB abundance and different environmental conditions (pH, TC, TN, moisture, and temperature) on nitrification performance. The soils of the long-term fertilized tea orchards and forests were sampled in the field, and nitrification experiments were conducted in the laboratory. The acid soils were collected from the field and used in laboratory incubation experiments to calculate the nitrification rate, including the net nitrification rate (NN rate), nitrification potential (NP), and nitrification kinetics. The basic parameters, different forms of nitrogen content, and AOA and AOB amoA gene copies were also analyzed. Compared with the forest soil, the tea orchard soil had a lower pH and higher nitrogen content (p < 0.05). The AOA and AOB abundance in the soils of the forests and tea orchards were pH-dependent. The NN rate and NP had good relationships with AOA or AOB in the forest soil; however, poor relationships were observed in the tea orchard soil. When pH < 4, the performances of AOA and AOB were restricted by pH and the environment, especially in long-term fertilized farmlands. Long-term fertilization can cause soil acidification, which regulates the abundance of AOA and AOB and their nitrifying ability. The soil environment rather than AOA or AOB could control nitrification in long-term fertilized farmlands with a pH below 4. These findings could improve fertilization efficiency and control nutrient runoff in hilly agricultural ecosystems.

Hydrogeochemical Characteristics and Quality Assessment of Mine Water in Coalfield Area, Guizhou Province, Southwest China.

Coal resources are widely distributed in Guizhou province, China and environmental pollution caused by coal mining is becoming increasingly serious, especially mine drainage. A total of 120 mine water samples collected from different coalfields were analyzed to investigate the hydrogeochemical characteristics and assess the water quality for drinking, domestic, and irrigative purposes. Water samples had a pH of 1.90-9.12 and most of them were acidic or weakly acidic. Total dissolved solids (TDS) ranged from 254 to 13,944 mg/L and correlated closely with the electrical conductivity (EC). The coal mine drainage of Guizhou was characterized typically by low pH value, high Fe and SO42- concentration, which were mainly attributed to oxidative weathering of pyrite. The most dominant type for abandoned coal-mine drainage was Ca-Mg-SO4, while that of the underground drainage for active mine were mainly Na-SO4 and Na-HCO3 because of high concentration of Na+ from the dissolution of evaporites and clastic rocks. High concentration of the TDS, SO42-, Fe, Mn, et al. made it unsuitable for drinking and domestic use, but part of the coal mine drainage could be used for irrigation at some sites.

Sources and transformation mechanisms of inorganic nitrogen: Evidence from multi-isotopes in a rural-urban river area.

Multi-isotope tracers were applied to quantitatively reveal the sources and transformation mechanisms of inorganic nitrogen both spatially and seasonally in a complex land use area in China. Based on land use and the level of socioeconomic development, the study area was divided into four zones: the rural area, developed urban area, developing urban area and industrial urban area. The redox condition and isotope analysis results indicated that the nitrification process dominated in the Han and Rong River, which were characterized by ammonium nitrogen (NH4+-N) and oxidizing conditions, while neither nitrification nor denitrification occurred in the Lian River. The inorganic nitrogen sources of the four areas were revealed from the results of a stable isotope analysis in R (SIAR) and a two-component mixing model after determining the transformation mechanisms. In the rural area, nitrate nitrogen (NO3--N) was mainly sourced from the increased fertilization of nitrogen fertilizer (42-56%) to farmland during the wet season, and from soil nitrogen (33-62%) related to increased nitrification during the dry season. In the urban area, the contributions of soil nitrogen, manure and sewage and industrial wastewater to the total inorganic nitrogen exhibited large seasonal and spatial differences, which were distinguished by the environmental management supported by gross domestic production (GDP). In the developed and developing urban areas, soil nitrogen contributed 41% and 47% of the NO3--N, respectively, during the wet season, and 47% and 54%, respectively, during the dry season. The second highest contribution was from manure and sewage (30-41%) with no seasonal differences. In the industrial urban area, the dominant contribution to the NH4+-N was from manure and sewage (81%) during the wet season, but industrial wastewater (84%) in the dry season. Our findings elucidate the multiplex sources and transformation mechanisms of inorganic nitrogen, and promote the management of nitrogen tracing to control nitrogen pollution in complex land use areas.

Recent advances on polymeric hydrogels as wound dressings.

Severe hemorrhage is a leading cause of high mortality in critical situations like disaster, accidents, and warfare. The resulting wounds could induce severe physical and psychological trauma to patients and also bring an immense socio-economic burden. Hence, rapid hemostasis and wound healing techniques have become critical initiatives for life-saving treatment. Although traditional methods relying on bandages and gauzes are effective in controlling hemorrhage, they suffer from several limitations: nonbiodegradability, being susceptible to infection, being unsuitable for the irregular wound, secondary tissue damage, and being almost ineffective for wound healing. Owing to the merits of high porosity, good biocompatibility, tunable physicochemical properties, and being beneficial for wound healing, hydrogels with excellent performance have drawn intensive attention and numerous novel effective hydrogel dressings have been widely developed. In this Review, after introducing some commonly used strategies for the synthesis of hydrogels, the most recent progress on polymer-based hydrogels as wound dressings is discussed. Particularly, their hemostasis, antibacterial, and biodegradation properties are introduced. Finally, challenges and future perspectives about the development of hydrogels for wound dressings are outlined.

Efficacy and safety of coenzyme A versus fenofibrate in patients with hyperlipidemia: a multicenter, double-blind, double-mimic, randomized clinical trial.

Background: We investigated the lipid-lowering efficacy and safety of coenzyme A (CoA) versus fenofibrate in Chinese patients with moderate dyslipidemia.Methods: A total of 417 subjects (aged 18-75 years) diagnosed with moderate dyslipidemia (triglyceride 2.3-6.5 mmol/L) from 13 large cardiovascular centers in China were recruited and randomly divided into a fenofibrate group (n = 207), which received 200 mg of fenofibrate orally once daily, and a CoA group (n = 210), which received 400 mg of CoA orally once a day. Blood lipoproteins, liver and renal function, creatine kinase, and blood glucose were measured at baseline, and after 4 and 8 weeks of treatment.Results: The baseline triglyceride (TG) level in the fenofibrate group and the CoA group was 3.39 ± 0.99 mmol/L and 3.60 ± 1.11 mmol/L, respectively. After treatment for 4 and 8 weeks with fenofibrate, TG was reduced by 31.62% and 33.13%. In the CoA group, TG was reduced by 17.29% and 23.80%. Compared with baseline, total cholesterol (TC) was significantly decreased in both groups after either 4 or 8 weeks of treatment (p < .05). CoA increased high-density lipoprotein cholesterol (HDL-C) after 4 weeks of treatment, whereas it had no significant effect on HDL-C after 8 weeks of treatment. Low-density lipoprotein cholesterol (LDL-C) was not modified in either group. The incidence of side effects was significantly lower in the CoA group compared with the fenofibrate group (p < .05).Conclusions: Compared with fenofibrate, CoA has less effect on reducing plasma TG levels in subjects with moderate dyslipidemia. However, it has fewer adverse effects.

Zwitterionic Peptide Enhances Protein-Resistant Performance of Hyaluronic Acid-Modified Surfaces.

A convenient and efficient approach for the surface modification of antifouling materials is highly desirable in numerous applications like affinity-based biosensors. Herein, we fabricated a hybrid antifouling coating on Au surfaces, with thiolated hyaluronic acid (HA) being chemically adsorbed to Au surfaces by the "graft to" approach, followed by a self-assembly of a smaller zwitterionic peptide named p-EK to obtain HA/p-EK-modified surfaces. The real-time sensorgrams of surface plasmon resonance biosensor manifested the successful modification of HA and p-EK on Au surfaces, indicating that there were some bare Au substrates on the HA-modified surfaces for peptide binding. The obtained HA/p-EK surfaces exhibited high hydrophilicity with a water contact angle of 9°. Quartz crystal microbalance and surface plasmon resonance experiments verified that further grafting the zwitterionic p-EK peptide on HA-modified surfaces could enhance the antifouling performance by one time. The improved protein resistance could be mainly contributed by the modification of the zwitterionic peptide that shields the exposed Au substrates from interacting with protein foulings. This strategy by grafting a smaller zwitterionic peptide might provide a novel way to achieve an enhanced protein-resistant performance of the macromolecular coating obtained by the "graft to" surface modification approach.

Interactions between Lubricin and Hyaluronic Acid Synergistically Enhance Antiadhesive Properties.

Preventing the unwanted adsorption of proteins and cells at articular cartilage surfaces plays a critical role in maintaining healthy joints and avoiding degenerative diseases such as osteoarthritis. Immobilized at the surface of healthy articular cartilage is a thin, interfacial layer of macromolecules consisting mainly of hyaluronic acid (HA) and lubricin (LUB; a.k.a. PRG4) that is believed to form a co-adsorbed, composite film now known to exhibit synergistic tribological properties. Bioinspired by the composition of cartilage surfaces, composite layers of HA and LUB were grafted to Au surfaces and the antiadhesive properties were assessed using surface plasmon resonance and quartz crystal microbalance. A clear synergistic enhancement in antiadhesive properties was observed in the composite films relative to grafted HA and LUB layers alone. Atomic force microscopy (AFM) normal force measurements provide insight into the architecture of the HA/LUB composite layer and implicate a strong contribution of hydrophobic interactions in the binding of LUB end-domains directly to HA chains. These AFM force measurements indicate that the adhesion of LUB to HA is strong and indicate that the hydrophobic coupling of LUB to HA shields the hydrophobic domains in these molecules from interactions with other proteins or molecules.

Effects of mining activities on evolution of water quality of karst waters in Midwestern Guizhou, China: evidences from hydrochemistry and isotopic composition.

Zhijin coal-mining district, located in Midwestern Guizhou Province, has been extensively exploited for several decades. The discharge of acid mine drainage (AMD) has constituted a serious threat to local water environmental quality, which greatly affected the normal use of local people. The Permian limestone aquifer is the essential potable water supply for local people, which covered under the widely distributed coal seams. To investigate the origin of the water, the evolutionary processes, and the sources of dissolved sulfate in the karst waters, the mine water, surface water, and groundwater near the coal mines were sampled for stable isotopes (H, O, and S) and conventional hydrochemical analysis. The results of hydrochemistry and isotopic composition indicate that the regional surface water and partial karst groundwater are obviously affected by coal-mining activities, which is mainly manifested in the increase of water solute concentration and the change of hydrochemical types. The isotopic composition of δ2HH2O and δ18OH2O indicates that the major recharge source of surface water and the groundwater is atmospheric precipitation and that it is influenced obviously by evaporation in the recharge process. The surface water is mainly controlled by the oxidation of pyrite, as well as the dissolution of carbonate rocks, whereas that of natural karst waters is influenced by the dissolution of carbonate rocks. The resulting δ34SSO4 values suggest that the dissolved sulfate source in the surface water is mainly pyrite oxidation but atmospheric precipitation for the karst groundwater. Given the similar chemistry and isotopic composition between surface water and partial groundwater, it is reasonable to assume that most of the dissolved sulfate source in part of the groundwater was derived through the oxidation of pyrite in the coal. Furthermore, the contamination of the surface water and partial groundwater from the coal seam has occurred distinctly in the catchment, which is enriched in SO42- and is mostly depleted δ34S in sulfate.

Dopamine-assisted deposition and zwitteration of hyaluronic acid for the nanoscale fabrication of low-fouling surfaces.

In this study, we proposed a bioinspired approach for the deposition and zwitteration of hyaluronic acid (HA) with a reduced glutathione (GSH) to form a composite layer that functions as a low fouling coating. A polyanion of the HA-dopamine conjugate (HADA) possessing catechol groups was synthesized by carbodiimide chemistry between HA and dopamine. Then, the dopamine conjugated biofunctional polymers (HADA) were grafted onto Au substrates via the transformation of catechol into a quinone group under mild oxidative conditions followed by a reaction with GSH to avoid undesired adhesion and also to shield the exposed Au substrate. Analysis of XPS spectra and wettability indicated that HADA and GSH were successfully grafted onto Au substrates. Surface plasmon resonance analysis showed that both HADA and further GSH modified surfaces exhibited reduced nonspecific adsorption. The attachment of GSH to HADA modified surfaces (HADA-G) resulted in better antifouling performance, with a low or ultralow protein adsorption of 0-7.51 ng cm-2 when exposed to single protein solutions, and a reduction in nonspecific adsorption from cow's milk to 10% compared to that of bare gold. The enhanced antifouling performance of HADA-G modified surfaces was likely due to the zwitterionic structure in GSH, which can induce stronger surface hydration through electrostatic interactions as well as the hydrogen bonding induced by HADA. Our results provide a facile and universal approach to surface modification and demonstrate the benefits of using a composite layer for the design of low fouling surfaces.

Conjugation of Hyaluronic Acid onto Surfaces via the Interfacial Polymerization of Dopamine to Prevent Protein Adsorption.

A versatile, convenient, and cost-effective method that can be used for grafting antifouling materials onto different surfaces is highly desirable in many applications. Here, we report the one-step fabrication of antifouling surfaces via the polymerization of dopamine and the simultaneous deposition of anionic hyaluronic acid (HA) on Au substrates. The water contact angle of the Au surfaces decreased from 84.9° to 24.8° after the attachment of a highly uniform polydopamine (PDA)/HA hybrid film. The results of surface plasmon resonance analysis showed that the Au-PDA/HA surfaces adsorbed proteins from solutions of bovine serum albumin, lysozyme, ß-lactoglobulin, fibrinogen, and soybean milk in ultralow or low amounts (4.8-31.7 ng/cm(2)). The hydrophilicity and good antifouling performance of the PDA/HA surfaces is attributable to the HA chains that probably attached onto their upper surface via hydrogen bonding between PDA and HA. At the same time, the electrostatic repulsion between PDA and HA probably prevents the aggregation of PDA, resulting in the formation of a highly uniform PDA/HA hybrid film with the HA chains (with a stretched structure) on the upper surface. We also developed a simple method for removing this PDA/HA film and recycling the Au substrates by using an aqueous solution of NaOH as the hydrolyzing agent. The Au surface remained undamaged, and a PDA/HA film could be redeposited on the surface, with the surface exhibiting good antifouling performance even after 10 such cycles. Finally, it was found that this grafting method is applicable to other substrates, including epoxy resins, polystyrene, glass, and steel, owing to the strong adhesion of PDA with these substrates.