Ultrafast and Broad-Band Graphene Heterojunction Photodetectors with High Gain.

Graphene possesses an exotic band structure that spans a wide range of important technological wavelength regimes for photodetection, all within a single material. Conventional methods aimed at enhancing detection efficiency often suffer from an extended response time when the light is switched off. The task of achieving ultrafast broad-band photodetection with a high gain remains challenging. Here, we propose a devised architecture that combines graphene with a photosensitizer composed of an alternating strip superstructure of WS2-WSe2. Upon illumination, n+-WS2 and p+-WSe2 strips create alternating electron- and hole-conduction channels in graphene, effectively overcoming the tradeoff between the responsivity and switch time. This configuration allows for achieving a responsivity of 1.7 × 107 mA/W, with an extrinsic response time of 3-4 µs. The inclusion of the superstructure booster enables photodetection across a wide range from the near-ultraviolet to mid-infrared regime and offers a distinctive photogating route for high responsivity and fast temporal response in the pursuit of broad-band detection.

Improved production of ß-carotene in light-powered Escherichia coli by co-expression of Gloeobacter rhodopsin expression.

BACKGROUND: Providing sufficient and usable energy for the cell factory has long been a heated issue in biosynthesis as solar energy has never been rooted out from the strategy for improvement, and turning Escherichia coli (E. coli) into a phototrophic host has multiple captivating qualities for biosynthesis. In this study, ß-carotene was a stable compound for production in E. coli with the expression of four enzymes (CrtE, CrtB, CrtI, CrtY) for production due to its light-harvesting feature as an antenna pigment and as an antioxidant and important precursor for human health. The expression of Gloeobacter rhodopsin (GR) in microbial organisms was proved to have potential for application. RESULTS: The expression of fusion protein, GR-GFP, in E. coli showed visible GFP signal under fluorescent microscopy, and its in vivo proton pumping activity signal can be detected in induced photocurrent by electrodes on the chip under intervals of illumination. To assess the phototrophic synthesis ability of the host strain compared to wild-type and vector control strain in chemostat batch with illumination, the expression of red fluorescent protein (RFP) as a target protein showed its yield improvement in protein assay and also reflected its early dominance in RFP fluorescence signal during the incubation, whereas the synthesis of ß-carotene also showed yield increase by 1.36-fold and 2.32-fold compared with its wildtype and vector control strain. To investigate the effect of GR-GFP on E. coli, the growth of the host showed early rise into the exponential phase compared to the vector control strain and glucose turnover rate was elevated in increased glucose intake rate and upregulation of ATP-related genes in glycolysis (PtsG, Pgk, Pyk). CONCLUSION: We reported the first-time potential application of GR in the form of fusion protein GR-GFP. Expression of GR-GFP in E. coli improved the production of ß-carotene and RFP. Our work provides a strain of E. coli harboring phototrophic metabolism, thus paving path to a more sustainable and scalable production of biosynthesis.

Identification of a Far-Red Light-Inducible Promoter that Exhibits Light Intensity Dependency and Reversibility in a Cyanobacterium.

As the demand for sustainable energy has increased, photoautotrophic cyanobacteria have become a popular platform for developing tools in synthetic biology. Although genetic tools are generally available for several model cyanobacteria, such tools have not yet been developed for many other strains potentially suitable for industrial applications. Additionally, most inducible promoters in cyanobacteria are controlled by chemical compounds, but adding chemicals into growth media on an industrial scale is neither cost-effective nor environmentally friendly. Although using light-controlled promoters is an alternative approach, only a cyanobacterial expression system inducible by green light has so far been described and employed for such applications. In this study, we have established a conjugation-based technique to express a reporter gene (eyfp) in the nonmodel cyanobacterium, Chlorogloeopsis fritschii PCC 9212. We also identified a promoter specifically activated by far-red light from the Far-Red Light Photoacclimation gene cluster of Leptolyngbya sp. JSC-1. This promoter, PchlFJSC1, was successfully used to drive eyfp expression. PchlFJSC1 is tightly regulated by light quality (i.e., wavelength) and leads to an approximately 30-fold increase in EYFP production when cells were exposed to far-red light. The induction level was controlled by the far-red light intensity, and induction stopped when cells were returned to visible light. This system has the potential for further applications in cyanobacteria by providing an additional choice of light wavelength to control gene expression. Collectively, this study developed a functional gene-expression system for C. fritschii PCC 9212 that can be regulated by exposing cells to far-red light.

Hepatic and Systemic Inflammation for Left Ventricular Mass in Physically Fit Adults: CHIEF Heart Study.

BACKGROUND: Both low-grade systemic and hepatic inflammation could result in increased left ventricular mass (LVM) in the general population. However, the associations, which might be modified by exercise, have not been clarified in physically active young adults. METHODS: The study included 2,004 military males aged 18-43 years in eastern Taiwan. Systemic and hepatic inflammation was defined by the upper tertiles of blood white blood cell (WBC) counts (7.51-11.00 x 103/µL) and serum alanine aminotransferase (ALT: 30-120 U/L), respectively. LVM indexed for the body height ≥49 g/m2.7 was defined as left ventricular hypertrophy (LVH) based on echocardiography. Multiple logistic regression analysis adjusting for age, smoking, alcohol intake, physical fitness, and metabolic syndrome was utilized to determine the associations. RESULTS: As compared to the lower WBC/lower ALT group, there tended to have an increased risk of LVH with the higher WBC/lower ALT group, the lower WBC/higher ALT group, and the higher WBC/higher ALT group [odds ratios: 0.89 (95% confidence intervals (CI): 0.41-1.94), 1.90 (95% CI: 0.86-4.22) and 2.48 (95% CI: 1.04-5.92); p-value for trend = 0.01]. CONCLUSION: Our study suggested that in physically active males, those with hepatic inflammation rather than low-grade systemic inflammation had a higher risk of LVH. Hepatic injury might be relevant to LVH as an early sign of end-organ damage regardless of physical fitness in young adults.

Patterning and doping of transition metals in tungsten dichalcogenides.

Substitutional transition metal doping in two-dimensional (2D) layered dichalcogenides is of fundamental importance in manipulating their electrical, excitonic, magnetic, and catalytic properties through the variation of the d-electron population. Yet, most doping strategies are spatially global, with dopants embedded concurrently during the synthesis. Here, we report an area-selective doping scheme for W-based dichalcogenide single layers, in which pre-patterned graphene is used as a reaction mask in the high-temperature substitution of the W sublattice. The chemical inertness of the thin graphene layer can effectively differentiate the spatial doping reaction, allowing for local manipulation of the host 2D materials. Using graphene as a mask is also beneficial in the sense that it also acts as an insertion layer between the contact metal and the doped channel, capable of depinning the Fermi level for low contact resistivity. Tracing doping by means of chalcogen labelling, deliberate Cr embedment is found to become energetically favorable in the presence of chalcogen deficiency, assisting the substitution of the W sublattice in the devised chemical vapor doping scheme. Atomic characterization using scanning transmission electron microscopy (STEM) shows that the dopant concentration is controllable and varies linearly with the reaction time in the current doping approach. Using the same method, other transition metal atoms such as Mo, V, and Fe can also be doped in the patterned area.

Unusual cause of light chain cast nephropathy.

Acute kidney injury due to light chain cast nephropathy is increasingly recognised in patients with haematological malignancies; however, the management and prognosis of this disease remain poorly understood. We describe a case of a 78-year-old woman with known chronic lymphocytic leukaemia (CLL) who presented with fatigue and weight loss. She was found to have acute kidney injury, which rapidly worsened during admission. Kidney biopsy showed light chain cast nephropathy and bone marrow biopsy confirmed B-cell CLL. She was started on ibrutinib, halting further deterioration in her renal function and avoiding renal replacement therapy in the first 8 months.

Impact of endoscopic sedation on gastric polyp detection: A one-center retrospective observational study.

Sedation esophagogastroduodenoscopy (EGD) has become more prevalent in many countries. However, owing to the limitation of health insurance payment for sedation EGD in Taiwan, non-sedation EGD still accounts for the majority of cases. This study was aimed to explore the differences between the sedation and non-sedation groups in terms of endoscopic findings, such as detection rate of gastric polyp of any size, number of detected gastric polyps, and location of the gastric polyps detected.We enrolled 10,940 patients who underwent EGD between January 1, 2016 and December 31, 2016 at the Tri-Service General Hospital; among the patients, 1900 received intravenous sedation (IVS) and 9040 did not. The data reviewed included demographics, parameters of the polyp (number, size, and location), and pathology.Compared with the non-sedation group, the sedation group had a higher overall polyp detection rate (P < .001); a greater number of detected polyps (Odds ratio 1.50, P = .007); and a higher detection rate of smaller polyps, such as fundic gland polyp, and hyperplastic polyp (P < .001). Among the pathological findings, gastric neuroendocrine tumor (NET) was detected using EGD in 2 cases and manifested as small polyps (<0.05 cm), and it showed significantly better detection rates in the sedation EGD group than in the non-sedation EGD group (P = .002).Sedation EGD could enhance a patients willingness and cooperation during EGD. Furthermore, sedation EGD increased the detection rates of small gastric polyps and was more likely to enable identification of unusual findings, such as gastric NET.

Association of Liver Transaminase Levels and Long-Term Blood Pressure Variability in Military Young Males: The CHIEF Study.

Background: An inverse relationship of serum liver transaminases and mortality might be due to better blood pressure control in hypertensive patients. Whether it holds true regarding such an association for long-term blood pressure variability (BPV) in those without antihypertensive therapy is unclear. Methods: A population of 1112 military males without antihypertensive medications, aged 32 years, was collected from a retrospective longitudinal study in Taiwan. Serum liver aspartate and alanine transaminase (AST and ALT) levels were obtained from a 12 h-fast blood sample of each participant. BPV was assessed by standard deviation (SD) and average real variability (ARV) of systolic and diastolic blood pressure (SBP and DBP), respectively across 4 visits during the study period (2012-2014, 2014-2015, 2015-2016, and 2016-2018). Multivariable linear regression analysis was utilized to determine the association adjusting for demographics, anthropometric indexes, SBP, DBP, and lipid profiles. Results: In the unadjusted model, ALT was significantly and positively correlated with SDDBP and ARVDBP (ß (standard errors) = 0.36 (0.16) and 0.24 (0.12), respectively), and so was AST (ß = 0.19 (0.08) and 0.14 (0.06), respectively). All the associations were insignificant with adjustments. However, ALT was significantly and negatively correlated with SDSBP and ARVSBP (ß = -0.35 (0.14) and -0.25 (0.11), respectively) and so was AST (ß = -0.14 (0.07) and -0.12 (0.06), respectively) with adjustments. Conclusion: Our findings suggested that serum liver transaminases were negatively correlated with long-term systolic BPV in young male adults without antihypertensive therapy, and the clinical relevance needs further investigations.

Surfactant-Mediated Growth and Patterning of Atomically Thin Transition Metal Dichalcogenides.

The role of additives in facilitating the growth of conventional semiconducting thin films is well-established. Apparently, their presence is also decisive in the growth of two-dimensional transition metal dichalcogenides (TMDs), yet their role remains ambiguous. In this work, we show that the use of sodium bromide enables synthesis of TMD monolayers via a surfactant-mediated growth mechanism, without introducing liquefaction of metal oxide precursors. We discovered that sodium ions provided by sodium bromide chemically passivate edges of growing molybdenum disulfide crystals, relaxing in-plane strains to suppress 3D islanding and promote monolayer growth. To exploit this growth model, molybdenum disulfide monolayers were directly grown into desired patterns using predeposited sodium bromide as a removable template. The surfactant-mediated growth not only extends the families of metal oxide precursors but also offers a way for lithography-free patterning of TMD monolayers on various surfaces to facilitate fabrication of atomically thin electronic devices.

miRTarBase 2020: updates to the experimentally validated microRNA-target interaction database.

MicroRNAs (miRNAs) are small non-coding RNAs (typically consisting of 18-25 nucleotides) that negatively control expression of target genes at the post-transcriptional level. Owing to the biological significance of miRNAs, miRTarBase was developed to provide comprehensive information on experimentally validated miRNA-target interactions (MTIs). To date, the database has accumulated >13,404 validated MTIs from 11,021 articles from manual curations. In this update, a text-mining system was incorporated to enhance the recognition of MTI-related articles by adopting a scoring system. In addition, a variety of biological databases were integrated to provide information on the regulatory network of miRNAs and its expression in blood. Not only targets of miRNAs but also regulators of miRNAs are provided to users for investigating the up- and downstream regulations of miRNAs. Moreover, the number of MTIs with high-throughput experimental evidence increased remarkably (validated by CLIP-seq technology). In conclusion, these improvements promote the miRTarBase as one of the most comprehensively annotated and experimentally validated miRNA-target interaction databases. The updated version of miRTarBase is now available at http://miRTarBase.cuhk.edu.cn/.

Diagnosis and referral delays in primary care for oral squamous cell cancer: a systematic review.

BACKGROUND: The incidence of oral cancer is increasing. Guidance for oral cancer from the National Institute for Health and Care Excellence (NICE) is unique in recommending cross-primary care referral from GPs to dentists. AIM: This review investigates knowledge about delays in the diagnosis of symptomatic oral squamous cell carcinoma (OSCC) in primary care. DESIGN AND SETTING: An independent multi-investigator literature search strategy and an analysis of study methodologies using a modified data extraction tool based on Aarhus checklist criteria relevant to primary care. METHOD: The authors conducted a focused systematic review involving document retrieval from five databases up to March 2018. Included were studies looking at OSCC diagnosis from when patients first accessed primary care up to referral, including length of delay and stage of disease at time of definitive diagnosis. RESULTS: From 538 records, 16 articles were eligible for full-text review. In the UK, more than 55% of patients with OSCC were referred by their GP, and 44% by their dentist. Rates of prescribing between dentists and GPs were similar, and both had similar delays in referral, though one study found greater delays attributed to dentists as they had undertaken dental procedures. On average, patients had two to three consultations before referral. Less than 50% of studies described the primary care aspect of referral in detail. There was no information on inter-GP-dentist referrals. CONCLUSION: There is a need for primary care studies on OSCC diagnosis. There was no evidence that GPs performed less well than dentists, which calls into question the NICE cancer option to refer to dentists, particularly in the absence of robust auditable pathways.

Sex-Specific Association Between Serum Uric Acid and Elevated Alanine Aminotransferase in a Military Cohort: The CHIEF Study.

AIM: The study was conducted in order to examine the sex-specific association of serum uric acid (SUA) levels with elevated serum alanine aminotransferase (ALT) in a Taiwanese military cohort. METHODS: We made a cross-sectional examination of the sex-specific relationship using 6728 men and 766 women, aged 18-50 years from a large military cohort in Taiwan. SUA levels within the reference range (<7.0 mg/dL for men and <5.7 mg/dL for women respectively) were divided into quartiles and SUA levels greater than the upper reference limits were defined as hyperuricemia. Elevated ALT levels were defined as ≥40 U/L. Multivariate logistic regression analysis was performed to determine the association between each SUA category and elevated ALT levels in men and women, respectively. RESULTS: The prevalence of hyperuricemia and elevated ALT in men were 18.7% and 12.7%, respectively, and in women were 3.3% and 2.1%, respectively. As compared with the lowest SUA quartile, hyperuricemia was associated with elevated ALT in men (odds ratios (OR): 1.62, 95% confidence intervals (CI): 1.19-2.20) after controlling for age, service specialty, body mass index, metabolic syndrome components, current cigarette smoking, alcohol intake status, and weekly exercise times, but the associations for the other SUA quartiles were null. By contrast, the associations of hyperuricemia (OR: 0.81, 95% CI: 0.10-6.64) and the other SUA quartiles with elevated ALT were null in women. CONCLUSION: Our findings suggest that the relationship between each SUA level and elevated ALT may differ by sex among military young adults. The mechanism for the sex difference requires further investigations.

Sex-Specific Association between Metabolic Abnormalities and Elevated Alanine Aminotransferase Levels in a Military Cohort: The CHIEF Study.

The association of metabolic syndrome (MetS) components with elevated serum alanine aminotransferase (ALT) levels, a marker of hepatic injury, may differ between men and women. However, the sex-specific association in a military young population which has a low prevalence of MetS was unclear. We conducted a cross-sectional examination in 6738 men and 766 women, aged 18-50 years, from the cardiorespiratory fitness study in armed forces (CHIEF) in eastern Taiwan. The components of MetS were defined according to the updated International Diabetes Federation (IDF) ethnic criteria for Asians. Elevated ALT levels were defined as ≥40 U/L for both sexes and ≥30 U/L for women alternatively. Multivariate logistic regression analysis was performed to determine the sex-specific association between MetS components and elevated ALT. The prevalence of MetS and elevated ALT in men were 11.9% and 12.7% respectively, and in women were 3.5%, and 3.8% respectively. In men, high-density lipoprotein < 40 mg/dL, blood pressures ≥ 130/85 mmHg, serum triglycerides ≥ 150 mg/dL, and waist size ≥ 90 cm were associated with elevated ALT (odds ratios (OR) and 95% confidence intervals: 1.59 (1.34-1.90), 1.40 (1.19-1.65), 2.00 (1.68-2.39), and 1.68 (1.38-2.04); all p < 0.001); whereas in women, only fasting plasma glucose ≥ 100 mg/dL was associated with elevated ALT ≥ 40 U/L (OR: 7.59 (2.35-24.51), p = 0.001) and ALT ≥ 30 U/L (2.67 (0.89-7.95), p = 0.08). Our findings suggest that the relationship between metabolic abnormalities and elevated ALT may differ by sex, possibly due to the MetS more prevalent in young adult men than in women.

The role of thiazolidinediones in hepatocellular carcinoma risk reduction: a population-based cohort study in Taiwan.

OBJECTIVES: The aim of this study was to investigate the effect of thiazolidinediones (TZDs) on the risk of hepatocellular carcinoma (HCC) development among diabetes mellitus (DM) patients. METHODS: We conducted a population-based case-control study in Taiwan based on data from the Taiwan National Health Insurance Research Database. A total of 76,349 newly diagnosed DM patients were identified from claims between 2000 and 2010. Among diabetics, 3,026 and 12,104 patients respectively, received or did not receive TZDs. Comparison frequency was matched with age, sex, and index date, excluding those with cancer at baseline. The incidence of HCC at the end of 2010 and the risks associated with the presence of hepatitis B and C infections were analyzed. The effect of TZDs use on the reduction of HCC risk was also assessed. RESULTS: The incidence of HCC was lower in the TZD cohort compared with the non-TZD cohort (418.3 vs. 484.6 per 100,000 person-years), with an adjusted hazard ratio (HR) of 0.53 (95% confidence interval = 0.38-0.77) using multivariable Cox proportional hazard regression. In the stratified analysis, HCC risk reduction was greater for diabetics without the comorbidities of cirrhosis, hepatitis B, hepatitis C, nonalcoholic fatty liver disease, end-stage renal disease, and hyperlipidemia, in the TZD cohort than in the non-TZD cohort. Male sex, cirrhosis, hepatitis B, and hepatitis C were significant independent factors predicting HCC (HRs of 1.43, 13.96, 2.31, and 2.15, respectively). CONCLUSIONS: This study suggests that the use of TZDs may reduce the risk of developing HCC among DM patients. Comorbidity with cirrhosis and/or hepatitis B/C infection appears to be associated with an extremely increased risk of developing HCC in this patient subset. These high-risk patients should be closely monitored.

Chronic hepatitis B, nonalcoholic steatohepatitis and physical fitness of military males: CHIEF study.

AIM: To investigate the association of chronic hepatitis B and nonalcoholic steatohepatitis with physical fitness in a Taiwanese military male cohort. METHODS: We made a cross-sectional examination of this association using 3669 young adult military males according to cardiorespiratory fitness and hospitalization events recorded in the Taiwan Armed Forces study. Cases of chronic hepatitis B (n = 121) were defined by personal history and positive detection of hepatitis B surface antigen. Cases of nonalcoholic steatohepatitis (n = 129) were defined by alanine transaminase level > 60 U/L, liver ultrasound finding of steatosis, and absence of viral hepatitis A, B or C infection. All other study participants were defined as unaffected (n = 3419). Physical fitness was evaluated by performance in 3000-m run, 2-min sit-ups, and 2-min push-ups exercises, with all the procedures standardized by a computerized scoring system. Multiple linear regression analysis was used to determine the relationship. RESULTS: Chronic hepatitis B negatively correlated with 2-min push-up numbers (ß = -2.49, P = 0.019) after adjusting for age, service specialty, body mass index, systolic and diastolic blood pressures, current cigarette smoking, alcohol intake status, serum hemoglobin, and average weekly exercise times. Nonalcoholic steatohepatitis was borderline positively correlated with 3000-m running time (ß = 11.96, P = 0.084) and negatively correlated with 2-min sit-up numbers (ß = -1.47, P = 0.040). CONCLUSION: Chronic hepatitis B viral infection and nonalcoholic steatohepatitis affects different physical performances in young adult military males, and future study should determine the underlying mechanism.

Cheap, High-Performance, and Wearable Mn Oxide Supercapacitors with Urea-LiClO4 Based Gel Electrolytes.

Here we report a simple, scalable, and low-cost method to enhance the electrochemical properties of Mn oxide electrodes for highly efficient and flexible symmetrical supercapacitors. The method involving printing on a printer, pencil-drawing, and electrodeposition is established to fabricate Mn oxide/Ni-nanotube/graphite/paper hybrid electrodes operating with a low-cost, novel urea-LiClO4/PVA as gel electrolyte for flexible solid-state supercapacitor (FSSC) devices. The Mn oxide nanofiber/Ni-nanotube/graphite/paper (MNNGP) electrodes in urea-LiClO4/PVA gel electrolyte show specific capacitance (Csp) 960 F/g in voltage region 0.8 V at 5 mV/s and exhibit excellent rates of capacitance retention more than 85% after 5000 cycles. Moreover, the electrochemical behavior of the MNNGP electrodes in urea-LiClO4/PVA at operating temperatures 27-110 °C was investigated; the results show that the MNNGP electrodes in urea-LiClO4/PVA exhibit outstanding performance (1100 F/g), even at 90 °C. The assembled FSSC devices based on the MNNGP electrodes in urea-LiClO4/PVA exhibit great Csp (380 F/g in potential region of 2.0 V at 5 mV/s, exhibiting superior energy density 211.1 W h/kg) and great cycle stability (less than 15% loss after 5000 cycles at 25 mV/s). The oxidation-state change was examined by in situ X-ray absorption spectroscopy. FSSC devices would open new opportunities in developing novel portable, wearable, and roll-up electric devices owing to the cheap, high-performance, wide range of operating temperature, and simple procedures for large-area fabrication.

Rationale and design of the cardiorespiratory fitness and hospitalization events in armed forces study in Eastern Taiwan.

AIM: To investigate the association between cardiorespiratory fitness and hospitalization events in a cohort of large voluntary arm forces in Taiwan. METHODS: The cardiorespiratory fitness and hospitalization events in armed forces (CHIEF) is a retrospective cohort consisting of more than 4000 professional military members aged 18-50 years in Eastern Taiwan. All participants received history taking, physical examination, chest radiography, 12-lead electrocardiography, blood tests for cell counts and fasting glucose, lipid profiles, uric acid, renal function and liver function in the Hualien Armed Forces General Hospital during 2014. In addition, participants were required to undergo two indoor resistant exercise tests including 2-min push-up and 2-min sit-up, both scored by infrared sensing, and one outdoor endurance 3000-m none weight-bearing running test, the main indicator of cardiorespiratory fitness in the Military Physical Training and Testing Center in Eastern Taiwan in 2014. RESULTS: Hospitalization events for cardiovascular disease, acute kidney injury, rhabdomyolysis, severe infectious disease, acute psychiatric illness, diabetes, orthopedic surgery and mortality will be identified in the National Insurance Research Database for 10 years. CONCLUSION: CHIEF will be among the largest Eastern Asian armed forces cohort, in which physical status was strictly evaluated to follow up the hospitalization events for severe illness.

Current systemic treatment of hepatocellular carcinoma: A review of the literature.

Hepatocellular carcinoma (HCC) is the fifth most common form of human cancer worldwide and the third most common cause of cancer-related deaths. The strategies of various treatments for HCC depend on the stage of tumor, the status of patient's performance and the reserved hepatic function. The Barcelona Clinic Liver Cancer (BCLC) staging system is currently used most for patients with HCC. For example, for patients with BCLC stage 0 (very early stage) and stage A (early stage) HCC, the curable treatment modalities, including resection, transplantation and radiofrequency ablation, are taken into consideration. If the patients are in BCLC stage B (intermediate stage) and stage C (advanced stage) HCC, they may need the palliative transarterial chemoembolization and even the target medication of sorafenib. In addition, symptomatic treatment is always recommended for patients with BCLC stage D (end stage) HCC. In this review, we will attempt to summarize the historical perspective and the current developments of systemic therapies in BCLC stage B and C in HCC.

Study of chromium modified TiO2 nano catalyst under visible light irradiation.

Visible light active photocatalysts were successfully prepared by incorporating chromium into anatase TiO2 at two Cr/Ti atomic ratios (0.03% and 0.11%) by the use of a modified sol-gel process. Results show that the size of the chromium modified TiO2 particles is approximately 14-25 nm. As indicated by diffuse reflectance ultra violet/visible absorption spectra, heavier chromium dosage tends to result in greater absorption in both ultra violet and visible light. The simulation results from Cr K-edge X-ray absorption spectra suggest that Cr(0) and Cr(III), accounting for approximately 25% and 75% of total Cr, respectively, coexist in the TiO2 catalyst doped with 0.11% Cr. Cr dopant is suggested to be responsible for the phenomenon of enhanced light absorption in both ultra violet and visible regions. Further, Cr(0) can act as an electron remover because of the formation of the Schottky barrier between Cr(0) and TiO2, thus reducing the possibility of electron hole recombination. Photo-catalytic degradation of methylene blue under irradiation of blue light (with peak flux at 460 nm wavelength and a small flux near 367 nm) was considerably enhanced under appropriate reaction time (12 and 24 h) as small amount of Cr was doped into anatase titanium dioxide catalyst. After prolonged reaction time, Cr(0) was suggested to be poisoned and/or oxidized by SO4(2-), one of the final products of mineralizing methylene blue, thus loosing the capability of the electron hole separation.

Chromium speciation in mildly heated Cr(VI)-doped latosol soil.

Cr(VI) chemical reduction in natural organic matter (NOM)-bearing latosol soil was investigated under various heating conditions at < or = 378 K. An enhanced Cr(VI) reduction rate has been observed for the reaction at 353-378 K. The effect of Fe(II) naturally occurring in the latosol soil on Cr(VI) chemical reduction is negligible compared with the effect of NOM. Cr(OH)(3) was quantitatively specified by X-ray absorption spectroscopy to be the key chromium species ( approximately 80%) after approximately 90% of Cr(VI) was chemically reduced by NOM at 353-378 K. This study indicates a potential strategy for using the heat extracted from industrial flue gas with a heat exchanger to chemically reduce Cr(VI) in NOM-bearing or organics-amended soils that contain Cr(VI).