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BACKGROUND: 1,3‐Propanediol (PDO) is a raw material/specialty chemical/additive in several industrial applications. A new wild‐type Clostridium strain BOH3 can utilize crude glycerol (CG) and produce PDO. This investigation reveals its potential for PDO production from CG. RESULTS: Initially, inoculum of strain BOH3 was cultured from reinforced clostridial medium (RCM) with glucose (medium‐A), and modified‐RCM with glycerol (medium‐B). While fermenting 20 g L−1 glycerol, the cells cultivated from medium‐A produced 5.75 g L−1 PDO (as major product) with 3.10 g L−1 butanol (byproduct), whereas the cells cultivated from medium‐B produced 11.01 g L−1 PDO with 2.50 g L−1 butyric acid and 1.01 g L−1 acetic acid, with no butanol produced. To enhance PDO production from the batch‐process, various parameters including pure glycerol/CG concentration (80 g L−1), inoculum age (15 h) and size (12.50%v/v) of cells from medium‐B, initial medium‐pH (pH 6.4) and incubation temperature (39 °C) were studied; the optimal values obtained are given in their respective parenthesis. Under optimal conditions, PDO production was 42.58–47.15 g L−1 (0.65–0.79 mol‐PDO/mol‐glycerol) from CG‐based rich/mineral media. Furthermore, fed‐batch fermentation with 50–80 g L−1 initial CG‐concentration was tested to enhance the PDO production. Among these, 60 g L−1 initial CG‐concentration assisted strain BOH3 in utilizing a high level of CG (~174 g L−1); it supported a higher‐titer of PDO production (103.55–116.45 g L−1), with the highest yield (0.72–0.81 mol−PDO/mol−glycerol) ever reported. CONCLUSION: Clostridium strain BOH3 shows the potential to support a high titer (>116 g L−1) with the highest yield (>0.80 mol mol−1) of PDO production from CG (a waste). It can be considered for industrial‐scale PDO production. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Tropical cyclone (TC) activities in the North Indian Ocean (NIO) peak in May during the pre-monsoon period, but the TC frequency shows obvious inter-annual variations. By conducting statistical analysis and dynamic diagnosis of long-term data from 1948 to 2016, the relationship between the inter-annual variations of Indian Ocean SST and NIO TC genesis frequency in May is analyzed in this paper. Furthermore, the potential mechanism concerning the effect of SST anomaly on TC frequency is also investigated. The findings are as follows: 1) there is a broadly consistent negative correlation between NIO TC frequency in May and SST in the Indian Ocean from March to May, with the key influencing area located in the southwestern Indian Ocean (SWIO); 2) the anomalies of SST in SWIO (SWIO-SST) are closely related to a teleconnection pattern surrounding the Indian Ocean, which can significantly modulate the high-level divergence, mid-level vertical motion and other related environmental factors and ultimately influence the formation of TCs over the NIO; 3) the increasing trend of SWIO-SST may play an essential role in the downward trend of NIO TC frequency over the past 69 years. [ABSTRACT FROM AUTHOR]

Corn stover is residual biomass that can be used for the production of fermentable sugars through enzymatic hydrolysis. However, a pretreatment step is required to enhance the enzymatic digestibility of biomass. Even though the alkaline hydrogen peroxide (AHP) method shows promise as an effective pretreatment for corn stover, a typical reaction time of 24 h is too long, and the amount of hydrogen peroxide required (~5% w/v) is too high. To address this problem, we developed a novel catalytic alkaline hydrogen peroxide (cAHP) method to shorten the pretreatment time and reduce hydrogen peroxide usage. This is the first time a metal catalyst, iron tetraamidomacrocyclic ligand (Fe-TAML) is combined with AHP to accelerate the oxidation of lignin using hydrogen peroxide under an alkaline condition. The reaction time can be shortened to 4.4 h from a typical reaction time of 24 h. With 5 ppm of Fe-TAML, the reducing sugar concentration is increased by 15% to 27.9 g/L, compared to the one without Fe-TAML. Next, the cAHP method is optimized by using response surface methodology (RSM). After the pretreatment of 10% corn stover in an alkaline solution (pH 10) with 8850 ppm H2O2 and 0.91 ppm catalyst for 4.4 h, the residual biomass can be recovered and hydrolyzed by using 10 U/mL at 12% solid loadings. After 24 h of hydrolysis, 36.2 g/L of reducing sugar is obtained, representing a 39.6% increase compared to traditional AHP using the same optimized condition. [ABSTRACT FROM AUTHOR]

The major predisposing factors of developing oral cancer include smoking, alcohol drinking, and betel quid chewing. Betel quid chewing could cause the abrasion and damage of oral mucosa by crude fibers, chemical insults by additive slaked lime, and arecoline from areca nut. These would lead to the local consequence of oral submucosal fibrosis, which is regarded clinically as a precancer lesion and a major cause of trismus. In addition, the components and additives in betel quid contain chemical toxins and carcinogens, which would further affect the oral mucosa and gradually develop a malignancy. Following literature review, aside from having a greater total tumor burden and more local diseases in the oral cavity and digestive tract, patients with betel quid-related oral cancer also have more systemic diseases from metabolic syndrome, hypertension, cardiovascular disease, type II diabetes mellitus, and obesity than those without this habit. In conclusion, those patients who have the history of smoking, alcohol drinking, and betel quid chewing would present much more unique clinical characteristics than those who only have a history of smoking and alcohol drinking. More attention should therefore be paid to pretreatment evaluation, treatment strategy, and posttreatment follow-up among betel quid chewers. [ABSTRACT FROM AUTHOR]

Fe−TAML is a well‐known green catalyst for bleaching and wastewater treatments. Quantitative analysis of Fe−TAML is important to understand its activity and lifetime in these applications. However, because of its sub‐parts‐per‐million dosage and the presence of interfering substances, it is very challenging to detect Fe−TAML specifically and quantitatively at this level. To overcome these issues, we develop a quantitative assay for Fe−TAML, which is based on its catalytic reaction with a blue dye (Reactive Blue 19) and H2O2. This assay is highly specific, and shows no interference for iron species. Moreover, the colorimetric assay can be carried out for fast screening of Fe−TAML with a limit of detection (LOD) of 0.39±0.08 μg L−1. Finally, this assay was successfully applied to understand the stability of Fe−TAML under various conditions, and monitoring the activity of Fe−TAML during wastewater treatments. [ABSTRACT FROM AUTHOR]

In the present study, a functional template made up of in situ synthesised gold nanoparticles (AuNPs) is prepared on polydimethylsiloxane (PDMS) for patterning of target protein onto the desired solid substrates. Unlike previous studies in which bioreceptor probes are randomly attached to the PDMS stamp through electrostatic interactions, herein, we propose an AuNPs–PDMS stamp, which provides a surface for the attachment of thiol-modified biorecognition probes to link to the stamp surface through a dative bond with a single anchoring point based on thiol chemistry. By using this platform, we have developed the ability for microcontact printing (µCP) to selectively capture and transfer target protein onto solid surfaces for detection purposes. After µCP, we also investigated whether liquid crystals (LCs) could be used as a label-free approach for identifying transfer protein. Our reported approach provides promise for biosensing of various analytes. [ABSTRACT FROM AUTHOR]

Background: This retrospective cohort study was to assess the prognostic value of preoperative albumin-to-alkaline phosphatase ratio (AAPR) on survival outcome for patients with locally advanced oral squamous cell carcinoma (LAOSCC). Methods: A total of 250 patients with LAOSCC receiving upfront radical surgery at a single institute from January 2008 to December 2017 were enrolled. The primary endpoint was the survival predictability of preoperative AAPR on the 5-year overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). Cox proportional hazards model was used for survival analysis. The X-tile software was used to estimate the optimal cut-off value of preoperative AAPR on survival prediction. A predictive nomogram incorporating the clinicopathological factors on OS was further generated. Results: The 5-year OS, CSS, and DFS rates were 68.6%, 79.7%, and 61.7%, respectively. The optimal cut-off of preoperative AAPR to predict the 5-year OS was observed to be 0.51. For those with preoperative AAPR≧0.51, the 5-year OS, CSS, and DFS were statistically significantly superior to those with preoperative AAPR<0.51 (OS: 76.1% vs 48.5%, P <.001; CSS: 84.3% vs 66.4%, P =.005; DFS: 68.9% vs 42.6%, P <.001). In Cox model, we observed that preoperative AAPR<0.51 was a significantly negative prognosticator of OS (HR: 2.22, 95% CI: 1.466-3.361, P <.001), CSS (HR: 2.037, 95% CI: 1.16-3.578, P =.013), and DFS (HR: 1.756, 95% CI: 1.075-2.868, P =.025). After adding the variable of preoperative AAPR, the c-index of the predictive nomogram incorporating assorted clinicopathological factors increases from 0.663 to 0.692 for OS. Conclusion: Our results suggest that preoperative AAPR serves as an independent survival predictor for patients with LAOSCC. The nomogram incorporating preoperative AAPR and various clinicopathological features may be a convenient tool to estimate the mortality risk for patients with LAOSCC. [ABSTRACT FROM AUTHOR]

Background: It is well known that p16 negative oropharyngeal squamous cell carcinoma (OPSCC) has a high probability of spreading to the ipsilateral neck. However, no consensus exists as to whether to perform elective treatment for clinical nodal negative in contralateral neck. Methods: A total of 85 patients with p16 negative OPSCC who underwent primary tumor excision and bilateral neck dissections between 2005 and 2018 were analyzed retrospectively. Clinicopathologic variables were used to identify factors predicting occult contralateral nodal metastasis (OCNM). A nomogram was developed to assess the risk of OCNM and the model was validated internally by using bootstrap resampling. Results: The overall prevalence of pathologically positive contralateral nodes was 30.6% (26/85) in our cohort, and the rate of OCNM was 18.3% (11/60). The presence of ipsilateral clinical extranodal extension (cENE) was significantly associated with contralateral neck metastasis (odds ratio, 5.662; 95% CI, 2.079– 15.415) with increased risk of OCNM (odds ratio, 4.271; 95% CI, 1.045– 17.458). Moreover, the concordance index of the proposed nomogram model without ipsilateral cENE was 0.623 and could increase to 0.717 with the inclusion of ipsilateral cENE in the calculation. Conclusion: The risk of OCNM in p16 negative OPSCC with ipsilateral cENE is notable. Ipsilateral cENE-based nomogram might assist in individual decision-making regarding contralateral nodal negative neck management and help avoid the over- and under-treatment of p16 negative OPSCC. [ABSTRACT FROM AUTHOR]

Objective: To compare the cardio- and cerebrovascular outcomes and survival rates of surgical and nonsurgical interventions for patients with obstructive sleep apnea (OSA) based on a national population-based database. Study Design: Retrospective cohort study. Setting: Taiwan National Health Insurance Research Database. Methods: We analyzed all cases of OSA among adults (age >20 years and confirmed with ICD-9-CM) from January 2001 to December 2013. We compared the patients with OSA who received upper airway surgery with age-, sex-, and comorbidity index–matched controls with continuous positive airway pressure (CPAP) treatment. The risk of myocardial infarction (MI) or stroke after treatment of OSA-related surgery versus CPAP was investigated. Results: During follow-up, 112 and 92 incident cases of MI occurred in the OSA surgery and CPAP treatment groups, respectively (rates of 327 and 298 per 100,000 person-years). Furthermore, 50 and 39 cases were newly diagnosed with stroke in the OSA surgery and CPAP treatment groups (rates of 144 and 125 per 100,000 person-years). Cox proportional hazard regressions showed that the OSA treatment groups (OSA surgery vs CPAP) were not significantly related to MI (hazard ratio, 1.03 [95% CI, 0.781-1.359]; P =.833) and stroke (hazard ratio, 1.12 [95% CI, 0.736-1.706]; P =.596) at follow-up, after adjustment for sex, age at index date, days from diagnosis to treatment, and comorbidities. Conclusion: Our study demonstrated that there was no difference of cardio- and cerebrovascular results between CPAP and surgery for patients with OSA in a 13-year follow-up. Level of Evidence: 3. [ABSTRACT FROM AUTHOR]

As an emerging stimuli-responsive material, liquid crystal (LC) has attracted great attentions beyond display applications, especially in the area of biochemical sensors. Its high sensitivity and fast response to various biological or chemical analytes make it possible to fabricate a simple, real-time, label-free, and cost-effective LC-based detection platform. Advancements have been achieved in the development of LC-based sensors, both in fundamental research and practical applications. This paper briefly reviews the state-of-the-art research on LC sensors in the biochemical field, from basic properties of LC material to the detection mechanisms of LC sensors that are categorized into LC-solid, LC–aqueous, and LC droplet platforms. In addition, various analytes detected by LCs are presented as a proof of the application value, including metal ions, nucleic acids, proteins, glucose, and some toxic chemical substances. Furthermore, a machine-learning-assisted LC sensing platform is realized to provide a foundation for device intelligence and automatization. It is believed that a portable, convenient, and user-friendly LC-based biochemical sensing device will be achieved in the future. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the importance of depth of invasion (DOI) in patients with pathologically low‐risk feature stage I oral squamous cell carcinoma (OSCC) managed by primary tumor resection alone. Methods: Patients with stage I OSCC, at pathologically low risk, underwent primary tumor resection without neck dissection were enrolled retrospectively between 2007 and 2015. Low risk was defined as the absence of positive or close margins, lymphovascular invasion, perineural invasion, worst pattern of invasion‐5, and poor differentiation in histologic grade. The primary endpoints included overall survival (OS), cancer specific survival (CSS), local recurrence free survival (LRFS), and regional recurrence free survival (RRFS). A nomogram based on the DOI was established for predicting RRFS. Results: A total of 198 patients were enrolled in this study. DOI was the only prognosticator to achieve statistical significance in all primary endpoints according to univariate analysis. Patients with DOI <3 mm tumor showed better five‐year OS, CSS, LRFS, and RRFS than those with DOI ≥3 mm tumor. The concordance index of the nomogram model without DOI was 0.684, which could increase to 0.733 when DOI was included in the calculation. Conclusion: Patients with pathologically low‐risk stage I OSCC correlate with a higher chance in occult neck metastasis if increasing DOI (≥3 mm) is noticed. Indeed, the chance of occult neck metastasis is significantly higher in this group (14% vs. 2%) than in those with DOI <3 mm. Elective neck dissection is advised if DOI is ≥3 mm to achieve better clinical outcomes. Level of Evidence: 4. [ABSTRACT FROM AUTHOR]

A knot is a worldwide used complication and one of the most ancient technologies in human history. A knot can be found in a wide range of applications such as providing practical structural robustness and mechanical connections between objectives. Here, we report a responsive knot that can self-adjust its geometry upon external stimuli. The knot is tightened in a thread made of a liquid crystal gel, the diameter and internal friction of which vary upon thermal/chemical stimulus. An overhand knot and a reef knot are demonstrated to exhibit auto-untie action responsive to external stimuli. A self-dropping device is shown to sense its surrounding temperature and chemical change in the environment, providing the proof-of-concept for sensing application. The results offer new alternatives for soft micro-robots and automation control for non-electric devices. [ABSTRACT FROM AUTHOR]

Production of esters from the acetone-butanol-ethanol (ABE) fermentation by Clostridium often focuses on butyl butyrate, leaving acetone as an undesired product. Addition of butyrate is also often needed because ABE fermentation does not produce enough butyrate. Here we addressed the problems using Clostridium beijerinckii BGS1 that preferred to produce isopropanol instead of acetone, and co-culturing it with Clostridium tyrobutyricum ATCC 25,755 that produced butyrate. Unlike acetone, isopropanol could be converted into ester using lipase and acids. C. tyrobutyricum ATCC 25,755 produced acids at pH 6, while C. beijerinckii BGS1 produced mainly solvents at the same pH. When the two strains were co-cultured, more butyrate was produced, leading to a higher titer of esters than the mono-culture of C. beijerinckii BGS1. As the first study reporting the production of isopropyl butyrate from the Clostridium fermentation, this study highlighted the potential use of lipase and co-culture strategy in ester production. [ABSTRACT FROM AUTHOR]

We report a heterogeneous reaction to reduce HAuCl4 solution and form gold nanoparticles (AuNPs) on stainless steel needle surfaces. Through bubbling of nitrogen, AuNPs dispersed into the solution homogeneously. Subsequently, AuNPs were immobilized on the surface of polydimethylsiloxane (PDMS). The immobilized AuNPs exhibit catalase-mimetic activity in a 2 wt% H2O2 solution. [ABSTRACT FROM AUTHOR]

Many volatile organic compounds (VOCs) are hazardous to human health and their concentrations need to be monitored over a large area. However, most chemical sensors can only be used for point detection. In this paper, we report a method to obtain a two-dimensional (2D) concentration profile of toluene vapor by using polymer-stabilized liquid crystals (PSLCs). After the PSLC sample is exposed to toluene vapor ranging from 9300 to 2800 ppm, the PSLC changes its interference color according to different local toluene concentrations. By using the interference color, we can obtain a 2D concentration profile of toluene inside the PSLC and study the diffusion of toluene inside the PSLC in great detail. We also determine the diffusion coefficient of dissolved toluene inside the PSLC to be 1.01 × 10−6 cm2 s−1. [ABSTRACT FROM AUTHOR]

The formation of the electrical double layer (EDL) in an aqueous solution in contact with the charged solid surfaces of a slit-type nanopore has been simulated by grand canonical Monte Carlo (GCMC) and canonical Monte Carlo (CMC) methods. In the GCMC simulations, a primitive EDL model in which water is considered as a continuum and the ions are considered as hard spheres is used. The results are found to be slightly different from those predicted by the Gouy-Chapman model at low electrolyte concentration and low surface charge density. The GCMC results were then used as an initial condition for the CMC sinmulations of a nonprimitive model in which the EDL is composed of molecular water (four-point transferable intermolecular potential, together with fluctuating charge model), cations (Na[SUP+]), and anions (Cl[SUP-]). The nonprimitive model provides a very different view of the EDL at the atomic level. For example, a single layer of water molecules, instead of counterions, is strongly adsorbed on negatively charged surfaces. This feature cannot be observed in the Gouy-Chapman or in the primitive model. Moreover, because the charged surfaces are covered by water molecules, the maximum counterion concentration in a nanopore occurs at the center, instead of on the surfaces, of the pore. This phenomenon is also supported by experimental data and theoretical calculations found in the literature. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations have been performed to study the arrangement of water molecules between charged surfaces. The molecular water used—the four- point transferable intermolecular potential (TIP4P), together with fluctuating charge (FQ)—constitutes the water model TIP4P-FQ. The TIP4P-FQ features the same molecular frame as the TIP4P model; however, with the former, charges on the molecular sites of the same molecule are allowed to fluctuate in response to their environment. Therefore, the induced dipole moment under an external field is inherently considered in the TIP4P-FQ water model. This feature makes it more useful than multipoint fixed-charge models, such as the TIP4P, in studying water arrangement between charged surfaces. The formation of a few ordering layers of water molecules adjacent to a charged surface is confirmed by (N,V,T) Monte Carlo simulations. The preferable orientation of water molecules in this study is found to be similar to previous findings in the literature, with the oxygen atoms pointing to the positively charged surface (oxygen-down) and the hydrogen atoms pointing to the negatively charged surface (oxygen-up). Modeling results also demonstrate that the dominant orientation at the negatively charged surface is one O-H bond pointing to the surface while another O-H bond is aligned parallel to the charged surface. In addition, simulation results using the TIP4P-FQ water model show that the water density in the interfacial region increases ∼8%-14%, which is lower than the density increase observed in experimental data discussed in the literature. [ABSTRACT FROM AUTHOR]

Chlorophenols have a strong medicinal smell and can be detected by the human nose at parts-per-million levels. Therefore, continuous monitoring of chlorophenols in water supplies is highly important. Herein, we reported a microfluidic sensor which can be used to detect 2,4-dichlorophenol (2,4-DCP) in real time with a limit of detection of around 0.1 ppm. The microfluidic sensor is a membrane-less galvanic cell which consists of two laminar flows running in parallel inside a straight channel. The sensor measures the potential difference between a solution containing 2,4-DCP and a reference solution containing acetate buffer. In a continuous-flow mode, the cell potential is proportional to the concentration of 2,4-DCP. To render specificity for the sensor, we incorporate a pre-treatment section where the incoming solution containing 2,4-DCP is split into two streams. One of the streams is brought into contact with cross-linked laccase aggregates (which catalyzes the hydrolysis of 2,4-DCP) and the second stream is taken as a reference solution. By comparing the potential difference between the two streams, we can determine the concentration of 2,4-DCP with high specificity. The microfluidic sensor platform is potentially useful for real-time detection of micropollutants present in aquatic systems with high sensitivity and specificity. [ABSTRACT FROM AUTHOR]

Background: The results showed that the deciding factor is the culture medium in which the bacteria and the graphene oxide (GO) are incubated at the initial manipulation step. These findings allow better use of GO and GO-based materials more and be able to clearly apply them in the field of biomedical nanotechnology. Results: To study the use of GO sheets applied in the field of biomedical nanotechnology, this study determines whether GO-based materials [GO, GO-polyoxyalkyleneamine (POAA), and GO-chitosan] stimulate or inhibit bacterial growth in detail. It is found that it depends on whether the bacteria and GO-based materials are incubated with a nutrient at the initial step. This is a critical factor for the fortune of bacteria. GO stimulates bacterial growth and microbial proliferation for Gram-negative and Gram-positive bacteria and might also provide augmented surface attachment for both types of bacteria. When an external barrier that is composed of GO-based materials forms around the surface of the bacteria, it suppresses nutrients that are essential to microbial growth and simultaneously produces oxidative stress, which causes bacteria to die, regardless of whether they have an outer-membrane-Gramnegative- bacteria or lack an outer-membrane-Gram-positive-bacteria, even for high concentrations of biocompatible GO-POAA. The results also show that these GO-based materials are capable of inducing reactive oxygen species (ROS)-dependent oxidative stress on bacteria. Besides, GO-based materials may act as a biofilm, so it is hypothesized that they suppress the toxicity of low-dose chitosan. Conclusion: Graphene oxide is not an antimicrobial material but it is a general growth enhancer that can act as a biofilm to enhance bacterial attachment and proliferation. However, GO-based materials are capable of inducing ROS-dependent oxidative stress on bacteria. The applications of GO-based materials can clearly be used in antimicrobial surface coatings, surface-attached stem cells for orthopedics, antifouling for biocides and microbial fuel cells and microbial electro-synthesis. [ABSTRACT FROM AUTHOR]

ABSTRACT Development of sustainable biobutanol production platforms from lignocellulosic materials is impeded by inefficient five carbon sugar uptake by solventogenic bacteria. The recently isolated Clostridium sp. strain BOH3 is particularly advantaged in this regard as it serves as a model organism which can simultaneously utilize both glucose and xylose for high butanol (>15 g/L) production. Strain BOH3 was, therefore, investigated for its metabolic mechanisms for efficient five carbon sugar uptake using a quantitative proteomics based approach. The proteomics data show that proteins within the CAC1341-1349 operon play a pivotal role for efficient xylose uptake within the cells to produce butanol. Furthermore, up-regulation of key enzymes within the riboflavin synthesis pathway explained that xylose could induce higher riboflavin production capability of the bacteria (e.g., ∼80 mg/L from glucose vs. ∼120 mg/L from xylose). Overall results from the present experimental approach indicated that xylose-fed BOH3 cultures are subjected to high levels of redox stress which coupled with the solvent stress-trigger a sporulation response within the cells earlier than the glucose-fed cultures. The study lays the platform for metabolic engineering strategies in designing organisms for efficient butanol and other value-added chemicals such as riboflavin production. Biotechnol. Bioeng. 2017;114: 1959-1969. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Polybrominated diphenyl ethers (PBDEs), chemicals commonly used as flame-retardants in consumer products, are emerging persistent organic pollutants that are ubiquitous in the environment. In this study, we report a PBDE-respiring isolate - Dehalococcoides mccartyi strain GY50, which debrominates the most toxic tetra- and penta-BDE congeners (∼1.4 µM) to diphenyl ether within 12 days with hydrogen as the electron donor. The complete genome sequence revealed 26 reductive dehalogenase homologous genes ( rdhAs), among which three genes ( pbrA1, pbrA2 and pbrA3) were highly expressed during PBDE debromination. After 10 transfers of GY50 with trichloroethene or 2,4,6-trichlorophenol as the electron acceptor instead of PBDEs, the ssrA-specific genome island ( ssrA-GI) containing pbrA1 and pbrA2 was deleted from the genome of strain GY50, leading to two variants (strain GY52 with trichloroethene, strain GY55 with 2,4,6-trichlorophenol) with identically impaired debromination capabilities (debromination of penta-/tetra-BDEs ceased at di-BDE 15). Through analysis of Illumina paired-end sequencing data, we identified read pairs that probably came from variants that contain ssrA-GI deletions, indicating their possible presence in the original strain GY50 culture. The two variant strains provide real-time examples on rapid evolution of organohalide-respiring organisms. As PBDE-respiring organisms, GY50-like strains may serve as key players in detoxifying PBDEs in contaminated environments. [ABSTRACT FROM AUTHOR]

Proteases play a pivotal role in regulating important physiological processes from food digestion to blood clotting. They are also important biomarkers for many diseases such as cancers. The importance of proteases has led to extensive efforts in the screening of proteases and their inhibitors as potential drug molecules. For example, human immunodeficiency virus (HIV) patients have been treated with HIV-1 protease inhibitors to prolong the life expectancy of patients. Such a close relationship between diseases and proteases provides a strong motivation for developing sensitive, selective, and robust protease assays and sensors, which can be exploited to discover new proteases and inhibitors. In this aspect, protease assays based on levels of proteolytic activities are more relevant than protease affinity assays such as immunoassays. In this review, recent developments of protease activity assays based on different detection principles are discussed and compared. For homogenous assays, fluorescence-based techniques are the most popular due to their high sensitivity and quantitative results. However, homogeneous assays have limited multiplex sensing capabilities. In contrast, heterogeneous assays can be employed to detect multiple proteases simultaneously, given the microarray technology that is already available. Among them, electrochemical methods, surface spectroscopy techniques, and enzyme-linked peptide protease assays are commonly used. Finally, recent developments in liquid crystal (LC)-based protease assays and their applications for detecting proteases and their inhibitors are discussed. [ABSTRACT FROM AUTHOR]

In this study, a rapid hot pressing process (HPP) has been adopted to enhance the photocatalytic water splitting efficiency of the TiO2–Fe2O3 metal oxide cocatalyst. Without complicated nanostructure fabrication, the hot pressed sample demonstrated more than 6-fold photocurrent enhancement compared to the untreated sample at an applied voltage of 1.2 V. This enhancement is attributed to the improvement of carrier transport properties in the TiO2–Fe2O3 matrix due to a significant reduction of the film thickness after the hot pressing process. In addition to the enhanced photocurrent, we observed a significant improvement of the stability and resistance to corrosion in a 1 M NaOH electrolyte due to the increase in the stiffness of the thin film from 80 GPa to 125 GPa after the hot pressing process. The improvements of carrier transport and charge separation are measured using photoluminescence (PL) spectroscopy and electrochemical impedance spectroscopy (EIS). The crystallinity and grain size of TiO2–Fe2O3 have been characterized by high-resolution transmission electron microscopy (HRTEM) before and after the hot pressing process. We also examined the plasmonic resonance effect by integration of plasmonic gold nanoparticles (NPs) into this hot pressed TiO2–Fe2O3 cocatalyst to achieve a further enhancement of hydrogen production. [ABSTRACT FROM AUTHOR]

Current anti-fibrotic effect of antioxidants in vivo is disappointing due probably to the fact that once liver fibrogenesis is established it is too advanced to be reversed by anti-oxidation mechanism. We consider antioxidant may only act on the early phase of fibrogenesis. Thus, we had previously established an early liver fibrosis animal model using an inducible expression vector (pPK9a), which contains TGF-β gene and was hydro-dynamically transferred into mice to induce a transient liver fibrosis. TGF-β1 has been well documented to up-regulate the expression of α2(1) collagen (Col 1A2) gene in the liver via the reactive oxygen species (ROS); the process triggers inflammation, leading to hepatic stellate cells (HSC) activation and liver fibrogenesis. Using our animal model and ROS, cyclooxygenase-2 (Cox-2) and Col 1A2 promoter assays as screening targets, we report here that a maleic acid derivative isolated from the Antrodia camphorata mycelium strongly decreases ROS production, promoter activity of Cox-2 and Col 1A2, intracellular calcium, expression of alpha-smooth muscle actin (α-SMA), Smad4-p-Smad2/3 co-localization in cell nucleus and the DNA binding activity of Sp1. Our results suggest that the maleic acid derivative prevents liver fibrosis at an early phase both in vitro and in vivo through the inhibition of ROS, inflammation and the activation of HSC. [ABSTRACT FROM AUTHOR]

Chemical 2,3-butanediol is an important platform compound possessing diverse industrial applications. So far, it is mainly produced by using petrochemical feedstock which is associated with high cost and adverse environmental impacts. Hence, finding alternative routes (e.g., via fermentation using renewable carbon sources) to produce 2,3-butanediol are urgently needed. In this study, we report a wild-type Klebsiella sp. strain XRM21, which is capable of producing 2,3-butanediol from a wide variety of carbon sources including glucose, sucrose, xylose, and glycerol. Among them, fermentation of sucrose leads to the highest production of 2,3-butanediol. To maximize the production of 2,3-butanediol, fermentation conditions were first optimized for strain XMR21 by using response surface methodology (RSM) in batch reactors. Subsequently, a fed-batch fermentation strategy was designed based on the optimized parameters, where 91.2 g/L of 2,3-butanediol could be produced from substrate sucrose dosing in 100 g/L for three times. Moreover, random mutagenesis of stain XMR21 resulted in a highly productive mutant strain, capable of producing 119.4 and 22.5 g/L of 2,3-butanediol and ethanol under optimized fed-batch fermentation process within 65 h with a total productivity of 2.18 g/L/h, which is comparable to the reported highest 2,3-butanediol concentration produced by previous strains. This study provides a potential strategy to produce industrially important 2,3-butanediol from low-cost sucrose. [ABSTRACT FROM AUTHOR]

Most biobutanol-producing Clostridium strains are unable to ferment polysaccharides such as cellulose and xylan due to the lack of hydrolyzing enzymes. In this study, we show that Clostridium beijerinckii G117, a newly isolated biobutanol-producing strain, expresses xylanase enzyme in the presence of 1 % beechwood xylan. The xylanase activity in the medium containing actively growing culture and 1 % of beechwood xylan can reach up to 2.66 U/ml after 14 h of fermentation. Using salting-out and size-exclusion chromatography, we purify the crude xylanase by 8.7-fold from the supernatant with a yield of 32.2 %. This purified xylanase has a molecular weight of 22.6 kDa, making it one of the smallest reported clostridial xylanases. Conserved domain analysis reveals that the xylanase belongs to glycoside hydrolase family 11 (GH11) but lacks a carbohydrate binding domain. When beechwood xylan is used as substrate for the xylanase, majority of the products are xylo-oligosaccharide (~98 %), suggesting that this is an endo-1,4- β-xylanase. [ABSTRACT FROM AUTHOR]

Chlorophenols are widely used as biocides, leading them to being prevalent environmental contaminants that pose toxic threats to ecosystems. In this study, a Dehalobacter species strain TCP1 was isolated from a digester sludge sample, which is able to dechlorinate 2,4,6-trichlorophenol (2,4,6-TCP) to 4-monochlorophenol (4-MCP) with H as the sole electron donor and acetate as the carbon source. Strain TCP1 also distinguishes itself from other Dehalobacter species with its capability to dechlorinate tetrachloroethene or trichloroethene (TCE) to both cis- and trans-dichloroethenes in a ratio of 5.6 (±0.2):1. The growth yields of strain TCP1 on TCE and 2,4,6-TCP were 4.14 × 10 and 5.77 × 10 cells mol of Cl released, respectively. Strain TCP1 contains five unusually long 16S rRNA gene copies per genome, and the extra length is due to the ~110 bp insertion sequences at their 5′-ends. This suggests that strain TCP1 may represent a novel Dehalobacter species. A putative chlorophenol reductive dehalogenase gene- debcprA-was identified to catalyze the ortho-chlorine removal from 2,4,6-TCP. Both the culture-dependent and housekeeping rpoB gene-based approaches indicate the purity of the culture. Strain TCP1 can serve as a promising candidate for the bioremediation of 2,4,6-TCP contaminated sites, and its discovery expands our understanding of metabolic capabilities of Dehalobacter species. [ABSTRACT FROM AUTHOR]

Butanol has been considered as a better alternative fuel and it can be produced from anaerobic Clostridial fermentation. Though several enzymes are involved in the biosynthesis of butanol in Clostridia, butanol dehydrogenase (BDH) is understood to play a major role, which catalyzes the conversion of butyraldehyde into butanol at the expenditure of a cofactor NAD(P)H. Recently, the strain Clostridium sp. BOH3 is reported to generate high level of butanol from monosugars. To investigate the BDH activity at various stages of fermentation, BOH3 was cultured in reinforced Clostridial medium with 30 g/l of glucose at 35 °C and the cells were harvested periodically from acid production and solvent production phases. During acid production, NADPH-dependent BDH activity is higher than NADH dependent BDH. Conversely, NADH-BDH activity is predominant during solvent production phase. The optimum pHs for NADH and NADPH-BDH are estimated as pH 6 and 8, respectively. By employing three steps of purification, NADH-BDH is purified to 102-fold with 36 % yield. Subsequent characterization reveals that NADH-BDH is a dimer composed of two subunits depicting the molecular weight of 44 kDa. The peptide finger printing analysis (MS/MS) suggests that the purified protein has higher homology with bifunctional acetaldehyde-CoA and alcohol dehydrogenase of Clostridium acetobutylicum. The extensive kinetic studies show that NADH-BDH follows an ordered sequential bi bi mechanism. The calculated values of K and K are 8.35 ± 0.25 and 0.076 ± 0.02 mM, respectively, whereas V is 4.02 ± 0.07 μmol/(mg protein. min). The purified NADH-BDH retains 70 % of its initial activity after 7 days at 4 °C. [ABSTRACT FROM AUTHOR]

Tetrachloroethene (PCE) and trichloroethene (TCE) are ideal solvents for numerous applications, and their widespread use makes them prominent groundwater pollutants. Even more troubling, natural biotic and abiotic processes acting on these solvents lead to the accumulation of toxic intermediates (such as dichloroethenes) and carcinogenic intermediates (such as vinyl chloride). Vinyl chloride was found in at least 496 of the 1,430 National Priorities List sites identified by the US Environmental Protection Agency, and its precursors PCE and TCE are present in at least 771 and 852 of these sites, respectively. Here we describe an unusual, strictly anaerobic bacterium that destroys dichloroethenes and vinyl chloride as part of its energy metabolism, generating environmentally benign products (biomass, ethene and inorganic chloride). This organism might be useful for cleaning contaminated subsurface environments and restoring drinking-water reservoirs. [ABSTRACT FROM AUTHOR]

We report a label-free and simple approach for the detection of glycoprotein-120 (gp-120) using an aptamer-based liquid crystals (LCs) biosensing platform. The LCs are supported on the surface of a modified glass slide with a suitable amount of B40t77 aptamer, allowing the LCs to be homeotropically aligned. A pronounced topological change was observed on the surface due to a specific interaction between B40t77 and gp-120, which led to the disruption of the homeotropic alignment of LCs. This results in a dark-to-bright transition observed under a polarized optical microscope. With the developed biosensing platform, it was possible to not only identify gp-120, but obtained results were analyzed quantitatively through image analysis. The detection limit of the proposed biosensing platform was investigated to be 0.2 µg/mL of gp-120. Regarding selectivity of the developed platform, no response could be detected when gp-120 was replaced by other proteins, such as bovine serum albumin (BSA), hepatitis A virus capsid protein 1 (Hep A VP1) and immunoglobulin G protein (IgG). Due to attributes such as label-free, high specificity and no need for instrumental read-out, the presented biosensing platform provides the potential to develop a working device for the quick detection of HIV-1 gp-120. [ABSTRACT FROM AUTHOR]

Micrometer-sized, periodic protein lines printed on a solid surface cause interference color which is invisible to the naked eye. However, the interference color can be amplified by using a thin layer of liquid crystal (LC) covered on the surface to form a phase diffraction grating. Strong interference color can thus be observed under ambient light. By using the LC-amplified interference color, we demonstrate naked-eye detection of a model protein-immunoglobulin G (IgG). Limit of detection can reach 20 μg/ml of IgG without using any instrumentation. This detection method is potentially useful for the development of low-cost and portable biosensors. [ABSTRACT FROM AUTHOR]