Wavelength dependency and photosensitizer effects in UV-LED photodegradation of iohexol.

Iodinated X-ray contrast media (ICM) are ubiquitously present in water sources and challenging to eliminate using conventional processes, posing a significant risk to aquatic ecosystems. Ultraviolet light-emitting diodes (UV-LED) emerge as a promising technology for transforming micropollutants in water, boasting advantages such as diverse wavelengths, elimination of chemical additives, and no induction of microorganisms' resistance to disinfectants. The research reveals that iohexol (IOX) degradation escalates as UV wavelength decreases, attributed to enhanced photon utilization efficiency. Pseudo-first-order rate constants (kobs) were determined as 3.70, 2.60, 1.31 and 0.65 cm2 J-1 at UV-LED wavelengths of 255, 265, 275 and 285 nm, respectively. The optical properties of dissolved organic matter (DOM) and anions undeniably influence the UV-LED photolysis process through photon competition and the generation of reactive substances. The influence of Cl- on IOX degradation was insignificant at UV-LED 255, but it promoted IOX degradation at 265, 275 and 285 nm. IOX degradation was accelerated by ClO2-, NO3-and HA due to the formation of various reactive species. In the presence of NO3-, the kobs of IOX followed the order: 265 > 255 > 275 > 285 nm. Photosensitizers altered the spectral dependence of IOX, and the intermediate photoactivity products were detected using electron spin resonance. The transformation pathways of IOX were determined through density functional theory calculations and experiments. Disinfection by-products (DBPs) yields of IOX during UV-LED irradiation decreased as the wavelength increased: 255 > 265 > 275 > 285 nm. The cytotoxicity index value decreased as the UV-LED wavelength increased from 255 to 285 nm. These findings are crucial for selecting the most efficient wavelength for UV-LED degradation of ICM and will benefit future water purification design.

Enhanced 2-MIB degradation by UV-LED/chlorine process: reaction kinetics, wavelength dependence, influencing factors and degradation pathways.

The efficient removal of 2-Methylisoborneol (2-MIB), a typical odour component, in water treatment plants (WTPs), poses a great challenge to conventional water treatment technology due to its chemical stability. In this study, the combination of ultraviolet light-emitting diode (UV-LED) and chlorine (UV-LED/chlorine) was exploited for 2-MIB removal, and the role of ultraviolet (UV) wavelength was investigated systematically. The results showed that UV or chlorination alone did not degrade 2-MIB effectively, and the UV/chlorine process could degrade 2-MIB efficiently, following the pseudo-first-order kinetic model. The 275 nm UV exhibited higher 2-MIB degradation efficiency in this UV-LED/chlorine system than 254 nm UV, 265 nm UV and 285 nm UV due to the highest mole adsorption coefficient and quantum yield of chlorine in 275 nm UV. ·OH and ·Cl produced in the 275 nm UV/chlorine system played major roles in 2-MIB degradation. HCO3- and Natural organic matter (NOM), prevalent in water, consumed ·OH and ·Cl, thus inhibiting the 2-MIB degradation by UV-LED/chlorine. In addition, NOM and 2-MIB could form a photonic competition effect. The degradation of 2-MIB by UV-LED/chlorine was done mainly through dehydration and demethylation, and odorous intermediates, such as camphor, were produced. 2-MIB was degraded through the α bond fracture and six-membered ring opening to form saturated or unsaturated hydrocarbons and aldehydes. Four DBPs, chloroform (CF), trichloroacetaldehyde (TCE), trichloroacetone (TCP) and dichloroacetone (DCP), were mainly generated, and CF was the most significant by-product.

Comparison of four pre-oxidants coupled powdered activated carbon adsorption for odor compounds and algae removal: Kinetics, process optimization, and formation of disinfection byproducts.

Pre-oxidation and powdered activate carbon (PAC) are usually used to remove algae and odorants in drinking waterworks. However, the influence of interaction between oxidants and PAC on the treatment performance are scarcely known. This study systematically investigated the combination schemes of four oxidants (KMnO4, NaClO, ClO2, and O3) and PAC on the inactivation of Microcystis aeruginosa cells and removal of four frequently detected odorants in raw water (diethyl disulfide (DEDS), 2,2'-oxybis(1chloropropane) (DCIP), 2-methylisoborneol (2-MIB) and geosmin (GSM)). O3 showed highest pseudo-first-order removal rate for all four compounds and NaClO exhibited highest inactivation rates for the cell viability and Chlorophyll a (Chl-a). The Freundlich model fitted well for the adsorption of DEDS and DCIP by PAC. When treated by combined oxidation/PAC, the removal ratio of algae cells and odorants were lower (at least 1.6 times) than the sum of removal ratios obtained in oxidation or PAC adsorption alone. Among these four oxidants, the highest synchronous control efficiency of odorants (52 %) and algae (66 %) was achieved by NaClO/PAC. Prolonging the dosage time interval promoted the removal rates. The pre-PAC/post-oxidation processes possessed comparable efficiency for the removal of odorants and algae cells comparing with pre-oxidation/post-PAC process, but significantly inhibited formation of disinfection byproducts (DBPs), especially for the formation of C-DBPs (for NaClO and ClO2), bromate (for O3) and chlorate/chlorite (for ClO2). This study could provide a better understanding of improving in-situ operation of the combined pre-treatments of oxidation and PAC for source water.

Si/Ge interfacial thermal conductance enhancement through Sn nanoparticle embedding.

The improvement of interfacial thermal conductance (ITC) is a crucial aspect of the thermal management of nanodevices. In this paper, the effect of embedding Sn nanoparticles at the Si/Ge interface on ITC was investigated using non-equilibrium molecular dynamics (NEMD) simulations. It was found that although Sn has a higher atomic weight than both silicon and germanium, the ITC can be enhanced by 1.95 times when the nanoparticles reach a suitable number and diameter. The phonon transmission functions and density of states clearly indicate that an increased ITC can be attributed to the enhanced inelastic phonon scattering facilitated by Sn nanoparticles. This enhancement opens up novel channels for interfacial phonon transport. However, when the number of nanoparticles surpasses a suitable value, elastic phonons begin to dominate heat transport, leading to a subsequent decrease in the ITC. Sensitivity analysis further underscores that the ITC exhibits greater responsiveness to changes in diameter. In addition, it is also shown that with increasing temperature, a higher frequency phonon excitation occurs, increasing phonon inelastic scattering and interface transmission. These findings offer a novel strategy for enhancing ITC and deepening our comprehension of both elastic and inelastic phonon processes in interfacial phonon transport.

Long-Term and Stable Dental Therapies via an In Situ Spontaneous Medicine Delivery System.

Chronic oral diseases are boring, long-term, and discomfort intense diseases, which endanger the physical and mental health of patients constantly. Traditional therapeutic methods based on medicines (including swallowing drugs, applying ointment, or injection in situ) bring much inconvenience and discomfort. A new method possessing accurate, long-term, stable, convenient, and comfortable features is in great need. In this study, we demonstrated a development of one spontaneous administration for the prevention and therapy on a series of oral diseases. By uniting dental resin and medicine-loaded mesoporous molecular sieve, nanoporous medical composite resin (NMCR) was synthesized by a simple physical mixing and light curing method. Physicochemical investigations of XRD, SEM, TEM, UV-vis, N2 adsorption, and biochemical experiments of antibacterial and pharmacodynamic evaluation on periodontitis treatment of SD rats were carried on to characterize an NMCR spontaneous medicine delivery system. Compared to existing pharmacotherapy and in situ treatments, NMCR can keep a quite long time of stable in situ medicine release during the whole therapeutic period. Taking the periodontitis treatment as an instance, the probing pocket depth value in a half-treatment time of 0.69 from NMCR@MINO was much lower than that of 1.34 from the present commercial Periocline ointment, showing an over two times effect.

Insight into mixed chlorine/chloramines conversion and associated water quality variability in drinking water distribution systems.

Mixed chlorine/chloramines are common in drinking water distribution systems (DWDSs); however, their transformation and impact on chemical and microbial characteristics are not well understood. We systematically investigated water quality parameters associated with mixed chlorine/chloramine species conversion in 192 samples (including raw, finished, and tap water) collected throughout the year in a city in East China. Various chlorine/chloramine species (free chlorine, monochloramine [NH2Cl], dichloramine [NHCl2], and organic chloramines [OC]) were detected in both chlorinated and chloraminated DWDSs. NHCl2 + OC increased with transport distance along the pipeline network. The maximum proportion of NHCl2 + OC in over total chlorine in tap water reached 66 % and 38 % from chlorinated and chloraminated DWDSs, respectively. Both free chlorine and NH2Cl showed a rapid decay in the water pipe systems, but NHCl2 and OC were more persistent. Correlations between chlorine/chloramine species and physicochemical parameters were established. Models for predicting the sum of chloroform/TCM, bromodichloromethane/BDCM, chlorodibromomethane/CBDM, and bromoform/TBM (THM4) (R2 = 0.56) and haloacetic acids (HAAs) (R2 = 0.65) exhibited greater accuracy based on machine learning tuned with chlorine/chloramine species, particularly NHCl2 + OC. The predominant bacterial communities in mixed chlorine/chloramine systems were those resistant to chlorine or chloramine such as proteobacteria. NH2Cl was the most significant explanatory factor (28.1 %) for the variation in microbial community assemblage in chloraminated DWDSs. Although residual free chlorine and NHCl2 + OC, accounted for a smaller proportion of chlorine species in chloraminated DWDSs, they played an essential role (12.4 % and 9.1 %, respectively) in the microbial community structure.

Repurposing FDA-approved drugs as HIV-1 integrase inhibitors: an in silico investigation.

The Human Immunodeficiency Virus (HIV) infection is a global pandemic that has claimed 33 million lives to-date. One of the most efficacious treatments for naïve or pretreated HIV patients is the HIV integrase strand transfer inhibitors (INSTIs). However, given that HIV treatment is life-long, the emergence of HIV strains resistant to INSTIs is an imminent challenge. In this work, we showed two best regression QSAR models that were constructed using a boosted Random Forest algorithm (r2 = 0.998, q210CV = 0.721, q2external_test = 0.754) and a boosted K* algorithm (r2 = 0.987, q210CV = 0.721, q2external_test = 0.758) to predict the pIC50 values of INSTIs. Subsequently, the regression QSAR models were deployed against the Drugbank database for drug repositioning. The top-ranked compounds were further evaluated for their target engagement activity using molecular docking studies and accelerated Molecular Dynamics simulation. Lastly, their potential as INSTIs were also evaluated from our literature search. Our study offers the first example of a large-scale regression QSAR modelling effort for discovering highly active INSTIs to combat HIV infection.Communicated by Ramaswamy H. Sarma.

Occurrence of fungal spores in drinking water: A review of pathogenicity, odor, chlorine resistance and control strategies.

Fungi in drinking water have been long neglected due to the lack of convenient analysis methods, widely accepted regulations and efficient control strategies. However, in the last few decades, fungi in drinking water have been widely recognized as opportunity pathogens that cause serious damage to the health of immune-compromised individuals. In drinking water treatment plants, fungal spores are more resistant to chlorine disinfection than bacteria and viruses, which can regrow in drinking water distribution systems and subsequently pose health threats to water consumers. In addition, fungi in drinking water may represent an ignored source of taste and odor (T&O). This review identified 74 genera of fungi isolated from drinking water and presented their detailed taxonomy, sources and biomass levels in drinking water systems. The typical pathways of exposure of water-borne fungi and the main effects on human health are clarified. The fungi producing T&O compounds and their products are summarized. Data on free chlorine or monochloramine inactivation of fungal spores and other pathogens are compared. At the first time, we suggested four chlorine-resistant mechanisms including aggregation to tolerate chlorine, strong cell walls, cellular responses to oxidative stress and antioxidation of melanin, which are instructive for the future fungi control attempts. Finally, the inactivation performance of fungal spores by various technologies are comprehensively analyzed. The purpose of this study is to provide an overview of fungi distribution and risks in drinking water, provide insight into the chlorine resistance mechanisms of fungal spores and propose approaches for the control of fungi in drinking water.

Renin-angiotensin system antagonists and mortality due to pneumonia, influenza, and chronic lower respiratory disease in patients with hypertension.

BACKGROUND: It is controversial whether angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEI/ARB) have a potentially beneficial role in the respiratory system. This study investigated the association between ACEI/ARB medications and respiratory-related mortality in hypertensive patients in a real-world nationally representative cohort. METHODS: This was a retrospective analysis based on a prospective cohort study. A total of 10,530 patients with hypertension aged ≥ 20 years were included. The data was extracted from the US National Health and Nutrition Examination Survey during 1988-1994 and 1999-2006. The study was approved by the Institutional Review Boards. Moreover, inform concent was taken form all the participants. RESULTS: Overall, 27.7% (n = 2920) patients took ACEI/ARB agents. During a median follow-up of 12.4 years, 278 individuals died of respiratory disease, including chronic lower respiratory disease (n = 155) and influenza or pneumonia (n = 123). Compared with the patients without ACEI/ARB use, those taking ACEI/ARB were not associated with respiratory-specific mortality in a multivariable-adjusted Cox model. After 1: 1 matching, taking ACEI/ARB was also not related to respiratory mortality (Hazard ratio (HR) = 1.07, 95% CI: 0.79-1.43), influenza- or pneumonia-related (HR = 1.00, 95% CI: 0.65-1.54) and chronic pulmonary mortality (HR = 1.13, 95% CI: 0.75-1.69). After separating ACEI and ARB from anti-hypertensive medications, those associations remained unchanged. CONCLUSIONS: We discovered no significant link between ACEI or ARB medication and pulmonary-related mortality in hypertensive patients. In hypertensive patients, standard ACEI/ARB administration may have little effect on the respiratory system.

Lymph node metastasis pattern and significance of left gastric artery lymph node dissection in esophagectomy for esophageal cancers.

PURPOSE: To investigate the lymph node metastasis pattern and significance of dissection of the left gastric artery lymph nodes in radical en bloc esophagectomy for esophageal squamous carcinomas based on the lymphatic drainage pathway revealed by carbon nanoparticle labeling. MATERIALS AND METHODS: Patients who underwent en bloc esophagectomy endoscopically were retrospectively enrolled. Carbon nanoparticles were injected in the submucosa of upper thoracic esophagus to label the relevant draining lymph nodes. The clinical data, lymph nodes dissected, surgical technique, and complications were analyzed. RESULTS: En bloc esophagectomy was successful in all 179 patients. Metastases to the left gastric artery lymph nodes were positive in 42 patients (23.5%) but negative in 137 (76.5%). The left gastric lymph nodes were labeled, whereas no celiac lymph nodes were labeled by carbon nanoparticles. A total of 4652 lymph nodes were resected, with 26 lymph nodes per patient. Seventy-three patients had lymph node metastasis (73/179). Seventeen patients had metastasis to the recurrent laryngeal nerve lymph nodes (9.5%). The metastasis rate of the lower thoracic esophageal cancer to the left gastric artery lymph nodes was 37.0%, significantly greater than that at the middle (15.4%) or upper (6.7%) thoracic segment. The lymph node metastasis rate was significantly (P < 0.05) increased with the length of the cancerous lesion, infiltration depth, and poor differentiation. Univariate analysis revealed that the metastasis rate to the left gastric artery lymph nodes was significantly (P < 0.05) associated with paraesophageal lymph node metastasis, para-cardial lymph metastasis, and TNM classification. Multivariate analysis indicated that cancer location (odds ratio 8.32, 95% confidence interval 2.12-32.24) was significantly (P < 0.05) associated with metastasis to the left gastric artery lymph nodes, with the cancer at the middle and lower thoracic segments significantly more than in the upper thoracic segment. CONCLUSION: Certain patterns exist in lymph node metastasis of esophageal cancer, and in radical esophagectomy of esophageal cancers, dissection of the left gastric artery lymph nodes is necessary to prevent possible residual or metastasis of esophageal squamous carcinomas based on the lymphatic drainage pathway of esophageal carcinomas demonstrated by carbon nanoparticle labeling.

Potassium variability during hospitalization and outcomes after discharge in patients with acute myocardial infarction.

BACKGROUND: The variability of metabolic biomarkers has been determined to provide incremental prognosis information, but the implications of electrolyte variability remained unclear. METHODS: We investigate the relationships between electrolyte fluctuation and outcomes in survivors of acute myocardial infarction (n = 4386). Ion variability was calculated as the coefficient of variation, standard deviation, variability independent of the mean (VIM) and range. Hazard ratios (HR) were estimated using the multivariable-adjusted Cox proportional regression method. RESULTS: During a median follow-up of 12 months, 161 (3.7%) patients died, and heart failure occurred in 550 (12.5%) participants after discharge, respectively. Compared with the bottom quartile, the highest quartile potassium VIM was associated with increased risks of all-cause mortality (HR = 2.35, 95% CI: 1.36-4.06) and heart failure (HR = 1.32, 95% CI: 1.01-1.72) independent of cardiac troponin I (cTnI), N terminal pro B type natriuretic peptide (NT-proBNP), infarction site, mean potassium and other traditional factors, while those associations across sodium VIM quartiles were insignificant. Similar trend remains across the strata of variability by other three indices. These associations were consistent after excluding patients with any extreme electrolyte value and diuretic use. CONCLUSIONS: Higher potassium variability but not sodium variability was associated with adverse outcomes post-infarction. Our findings highlight that potassium variability remains a robust risk factor for mortality regardless of clinical dysnatraemia and dyskalaemia.

Upregulation of miR-133a-3p enhances Bufothionine-induced gastric cancer cell death by modulating IGF1R/PI3K/Akt signal pathway mediated ER stress.

AIMS: Bufothionine had been used for gastric cancer (GC) treatment, and this study managed to uncover the underlying mechanisms. MATERIALS AND METHODS: Cell proliferation was determined by CCK-8 assay and colony formation assay. Flow cytometry (FCM) and TUNEL assay were used to measure cell apoptosis ratio. Intracellular ROS was measured by DCFH-DA probes. qRT-PCR was used to determine miRNAs levels. Western Blot was performed to probe proteins. Dual-luciferase reporter gene system was employed to validate the binding sites of miR-133a-3p and 3'UTR regions of IGF1R mRNA. Immunohistochemistry (IHC) was used to determine the expressions of Ki-67 in mice tumor tissues. KEY FINDINGS: Bufothionine inhibited cell viability, triggered ER stress and promoted ROS production in GC cells, and both ER stress inhibitor Salburinal (Sal) and ROS scavenger (NAC) abrogated Bufothionine induced GC cell death. Besides, miR-133a-3p was upregulated by Bufothionine, and Bufothionine-induced cell death was enhanced by miR-133a-3p overexpression while alleviated by miR-133a-3p knockdown. Furthermore, miR-133a-3p inactivated PI3K/Akt signal pathway by sponging IGF1R, and Bufothionine inhibited insulin-like growth factor 1 receptor (IGF1R) and inactivated PI3K/Akt cascade by upregulating miR-133a-3p. Notably, the promoting effects of overexpressed miR-133a-3p on Bufothionine-induced GC cell death were abrogated by overexpressing IGF1R, and aggravated by the PI3K/Akt cascade inhibitor (LY294002). SIGNIFICANCE: Bufothionine promoted GC cell death by triggering miR-133a-3p/IGF1R/PI3K/Akt axis mediated ER stress and ROS production.

[Deep fascia composite autologous red bone marrow transplantation for the treatment of fracture nonunion].

OBJECTIVE: According to bone regeneration under the membrane and the bone regeneration deep fascia composite autologous red bone marrow transplantation applied in the treatment of fracture nonunion, in order to find a simple and effective clinical treatment of nonunion. METHODS: Since March 2006 to March 2009,17 patients of fracture nonunion were treated by the deep fascia composite autologous bone marrow transplantation,included 10 males and 7 females, aged from 7 to 52 years old (means 32 years). There were 10 cases of tibia, 5 cases of radius, 2 cases of clavicle. Injured to admission time was from 7 to 36 months (means 12 months). Ten cases underwent operation for 1 time,5 cases for twice and 2 cases for 3 times. The position of nonunion were all at bone shaft and the condition of the skin and soft tissue was good. X-ray film showed 11 cases of hyperplasia nonunion, 6 cases of shrinking. The original fixation were removed and the intramedullary nail or plate fixation were re-used, and fracture ends were sutured closed by autogenous deep fascia and implanted with autologous red bone marrow. RESULTS: Seventeen patients were followed-up for from 5 months to 2 years with an average of 1 year. Fracture healing time was from 12 to 20 weeks (means 16 weeks). According to the criteria of fracture healing to assess efficacy, the results were excellent in 14 cases, good in 2 cases and poor in 1 case. CONCLUSION: Deep fascia composite autologous autologous red bone marrow transplantation for the treatment of fracture nonunion is suitable at the bone shaft and good condition of skin and soft tissue. The method has been observed that the fracture healing time is short.

Deep fascia composite autologous red bone marrow transplantation for the treatment of fracture nonunion / 中国骨伤

<p><b>OBJECTIVE</b>According to bone regeneration under the membrane and the bone regeneration deep fascia composite autologous red bone marrow transplantation applied in the treatment of fracture nonunion, in order to find a simple and effective clinical treatment of nonunion.</p><p><b>METHODS</b>Since March 2006 to March 2009,17 patients of fracture nonunion were treated by the deep fascia composite autologous bone marrow transplantation,included 10 males and 7 females, aged from 7 to 52 years old (means 32 years). There were 10 cases of tibia, 5 cases of radius, 2 cases of clavicle. Injured to admission time was from 7 to 36 months (means 12 months). Ten cases underwent operation for 1 time,5 cases for twice and 2 cases for 3 times. The position of nonunion were all at bone shaft and the condition of the skin and soft tissue was good. X-ray film showed 11 cases of hyperplasia nonunion, 6 cases of shrinking. The original fixation were removed and the intramedullary nail or plate fixation were re-used, and fracture ends were sutured closed by autogenous deep fascia and implanted with autologous red bone marrow.</p><p><b>RESULTS</b>Seventeen patients were followed-up for from 5 months to 2 years with an average of 1 year. Fracture healing time was from 12 to 20 weeks (means 16 weeks). According to the criteria of fracture healing to assess efficacy, the results were excellent in 14 cases, good in 2 cases and poor in 1 case.</p><p><b>CONCLUSION</b>Deep fascia composite autologous autologous red bone marrow transplantation for the treatment of fracture nonunion is suitable at the bone shaft and good condition of skin and soft tissue. The method has been observed that the fracture healing time is short.</p>