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The bacterial SOS response plays a key role in adaptation to DNA damage, including genomic stress caused by antibiotics. SOS induction begins when activated RecA*, an oligomeric nucleoprotein filament that forms on single-stranded DNA, binds to and stimulates autoproteolysis of the repressor LexA. Here, we present the structure of the complete Escherichia coliSOS signal complex, constituting full-length LexA bound to RecA*. We uncover an extensive interface unexpectedly including the LexA DNA-binding domain, providing a new molecular rationale for ordered SOS gene induction. We further find that the interface involves three RecA subunits, with a single residue in the central engaged subunit acting as a molecular key, inserting into an allosteric binding pocket to induce LexA cleavage. Given the pro-mutagenic nature of SOS activation, our structural and mechanistic insights provide a foundation for developing new therapeutics to slow the evolution of antibiotic resistance.

Background: Additional therapies for hepatic encephalopathy (HE) treatment are warranted. There are data evaluating the use of zinc for HE; however, clinical outcomes, specifically in the United States, are unknown.Objective: To compare 30-day and 1-year all-cause readmission rates in patients with cirrhosis complicated by HE on lactulose and rifaximin to those on lactulose, rifaximin, and zinc.Methods: This retrospective study included patients admitted with documented cirrhosis and home medications of lactulose and rifaximin, with or without zinc. Patients were stratified into 2 groups: those receiving lactulose and rifaximin for HE (control) and those receiving lactulose, rifaximin, and zinc for HE (treatment). The primary outcomes were 30-day and 1-year all-cause readmission rates.Results: One-hundred fifty-seven patients were included (102 in control group, 55 in treatment group). Regarding 30-day and 1-year all-cause readmission rates, there was no difference between the control and treatment groups.Conclusion and Relevance: This is the first study conducted in the United States evaluating zinc for HE treatment. Zinc did not impact 30-day or 1-year all-cause readmission rates. Further studies are warranted to evaluate the potential benefit of zinc for HE, possibly in correlation with Model for End-stage Liver Disease-Sodium (MELD-Na) scores.

Background: In patients with Roux-en-Y gastric bypass (RYGB) anatomy, laparoscopic endoscopic retrograde cholangiopancreatography (LA-ERCP) and enteroscopy-assisted ERCP (E-ERCP) have been utilized to achieve pancreaticobiliary access. Endoscopic ultrasound-directed transgastric endoscopic retrograde cholangiopancreatography (EDGE) has recently emerged as an alternate and efficient approach. As data regarding EDGE continues to evolve, concerns about safety and efficacy remain, limiting wide adoptability. We performed a systematic review and meta-analysis to assess the safety and efficacy of EDGE and compare it to the current standard of care. Methods: A comprehensive search of major databases (inception to Nov 2022) identified published studies on EDGE. A random-effects model was used to calculate the pooled rates and heterogeneity (I2). Risk ratio (RR) and standardized difference in means (SMD) were utilized for head-to-head comparison analysis between EDGE vs. LA-ERCP and EDGE vs. E-ERCP. Primary outcomes assessed pooled EDGE safety (adverse events) and efficacy (technical/clinical success). Secondary outcomes assessed efficacy and safety profiles via a comparative analysis of EDGE vs. LA-ERCP and EDGE vs. E-ERCP. Results: A total of 16 studies (470 patients) were included. EDGE pooled technical success (TS) rate was 96% (95% CI 92–97.6, I2= 0), and clinical success was 91% (85–95, I2= 0). Pooled rate of all adverse events with EDGE was 17% (14–24.6, I2= 32%). On sub-group analysis, these included failure of fistula closure 17% (10–25.5, I2= 48%), stent migration 7% (4–12, I2= 51%), bleeding 5% (3.2–7.9, I2= 0), post-EDGE weight gain 4% (2–9, I2= 0), perforation 4% (2.1–5.8, I2= 0), and post-ERCP pancreatitis 2% (1–5, I2= 0). EDGE TS was comparable to LA-ERCP (97% vs. 98%; RR, 1.00; CI, 0.85–1.17, p= 0.95) and E-ERCP (100% vs. 66%; RR, 1.26; CI, 0.99–1.6, p= 0.06).No statistical difference was noted in adverse events between EDGE and LA-ERCP (13% vs. 17.6%; RR, 0.61; CI, 0.28–1.35, p= 0.52) and E-ERCP (9.6% vs. 16%; RR, 0.61; CI, 0.28–1.35, p= 0.22). EDGE procedure time and hospital stay were shorter than LA-ERCP and E-ERCP (p< 0.001). Conclusion: Our analysis shows that EDGE is safe and efficacious to the current standard of care. Further head-to-head comparative trials are needed to validate our findings.

The SOS response is a bacterial DNA damage response pathway that has been heavily implicated in bacteria’s ability to evolve resistance to antibiotics. Activation of the SOS response is dependent on the interaction between two bacterial proteins, RecA and LexA. RecA acts as a DNA damage sensor by forming lengthy oligomeric filaments (RecA*) along single-stranded DNA (ssDNA) in an ATP-dependent manner. RecA* can then bind to LexA, the repressor of SOS response genes, triggering LexA degradation and leading to induction of the SOS response. Formation of the RecA*-LexA complex therefore serves as the key “SOS activation signal.” Given the challenges associated with studying a complex involving multiple macromolecular interactions, the essential constituents of RecA* that allow LexA cleavage are not well defined. Here, we leverage head-to-tail linked and end-capped RecA constructs as tools to define the minimal RecA* filament that can engage LexA. In contrast to previously postulated models, we found that as few as three linked RecA units are capable of ssDNA binding, LexA binding, and LexA cleavage. We further demonstrate that RecA oligomerization alone is insufficient for LexA cleavage, with an obligate requirement for ATP and ssDNA binding to form a competent SOS activation signal with the linked constructs. Our minimal system for RecA* highlights the limitations of prior models for the SOS activation signal and offers a novel tool that can inform efforts to slow acquired antibiotic resistance by targeting the SOS response.

Herein, we report three new metal-free, photochemically active single, dual, and combinatorial CORMs (photoCORMs) based on a carbazole-fused 1,3-dioxol-2-one moiety which released one equivalent of CO, two equivalent of CO, and a combination of one equivalent of each CO and anticancer drug upon one- and two-photon excitation, respectively. The photoCORMs exhibited good cellular uptake and real-time monitoring ability of CO uncaging by a color change approach in cancerous B16F10 cells. Interestingly, the cytotoxicity assay on B16F10 cells indicated that the dual photoCORM has increased anticancer activity over the single and combinatorial photoCORMs upon irradiation. Our results also showed that CO could accelerate the effectiveness of the well-known anticancer drug (chlorambucil). Finally, the in vivoevaluation of the dual photoCORM on an established murine melanoma tumor (C57BL/6J mouse model) manifested a significant regression of tumor volume and led to significant improvement (>50%) in the overall survivability.

A series of oxadiazole derivatives were synthesized and evaluated as 5-hydroxytryptamine-4 receptor (5-HT4R) partial agonists for the treatment of cognitive deficits associated with Alzheimer’s disease. Starting from a reported 5-HT4R antagonist, a systematic structure–activity relationship was conducted, which led to the discovery of potent and selective 5-HT4R partial agonist 1-isopropyl-3-{5-[1-(3-methoxypropyl) piperidin-4-yl]-[1,3,4]oxadiazol-2-yl}-1H-indazole oxalate (Usmarapride, 12l). It showed balanced physicochemical–pharmacokinetic properties with robust nonclinical efficacy in cognition models. It also showed disease-modifying potential, as it increased neuroprotective soluble amyloid precursor protein alpha levels, and dose-dependent target engagement and correlation of efficacy with oral exposures. Phase 1 clinical studies have been completed and projected efficacious concentration was achieved without any major safety concerns. Phase 2 enabling long-term safety studies have been completed with no concerns for further development.

The article focuses on initial implementations of automation showing promise across industries, smart automation has become an important priority. Topics inlcude the building conversational assistants at a bank or automating goods allocations to warehouses at a retail firm, the businesses in all sectors are investing significantly in their automation capability, and the smart automation initiatives are no longer simply nice to become a necessity an important element of business.

A wavelength-orthogonal photocleavable monochromophoric linker was developed that is based on a 3-acetyl-9-ethyl-6-methylcarbazole (AEMC) moiety substituted at both the phenacyl and benzylic positions with different carboxylic acids. The different carboxylic acids were released sequentially upon irradiation with light of λ ≥ 365 nm and λ ≥ 290 nm, respectively.

Fluorescent unnatural amino acids give biochemists, biophysicists, and bioengineers new ways to probe the properties of proteins and peptides. Here, the synthesis of acridon-2-ylalanine (Acd) is optimized for large-scale production to enable ribosomal incorporation through genetic code expansion (GCE), and fluorenylmethoxycarbonyl (Fmoc)-protected Acd is prepared for solid-phase peptide synthesis (SPPS). We demonstrate the utility of Acd in several applications: first, Acd quenching by Tyr is used in the design of fluorescent protease sensors made by SPPS. Second, we demonstrate Acd incorporation into a lanthanide-binding peptide that is generated either by GCE or by SPPS and demonstrate the utility of Acd for sensitizing the emission of Eu3+. Finally, Acd is inserted into the intrinsically disordered protein, α-synuclein, using GCE and used to study ion binding and aggregation.

A one- and two-photon activated photoremovable protecting group (PRPG) was designed based on a carbazole fused o-hydroxycinnamate platform for the dual (same or different) release of alcohols. The mechanism for the dual release proceeds through a stepwise pathway and also monitors the first and second photorelease in real time by an increase in fluorescence intensity and color change, respectively. Further, its application in staining live neurons and ex vivo imaging with two-photon excitation is shown.

Persulfides have been considered as potential signaling compounds similar to the H2S in “S-persulfidation”, a sulfur-mediated redox cycle. The research of this sulfur-mediated species is hindered because of the lack of efficient persulfide donors. In this current study, we have developed one- and two-photon-activated persulfide donors based on an o-nitrobenzyl (ONB) phototrigger, which releases the biologically active persulfide (N-acetyl l-cysteine persulfide, NAC-SSH) in a spatiotemporal manner. Next, we have demonstrated the detection of persulfide release both qualitatively and quantitatively using the well-known “turn on” fluorescence probe, that is, monobromobimane, and the trapping agent, that is, 2,4-dinitrofluorobenzene, respectively. Furthermore, we examined the cytotoxicity of synthesized persulfide donors on HeLa cells and the cytoprotective ability in the highly oxidizing cellular environment.

Borehole K-1 is an exploratory well that was drilled in the North Makassar Basin (West Sulawesi) in 2011. Gas chromatography (GC) and gas chromatography-mass chromatography (GC-MS) analyses have been conducted on extracts from well cuttings from the Paleogene to Neogene interval in order to investigate the characteristics of biomarkers present. Although the well was drilled with oil-based mud and gas chromatographic analysis reveals that the alkane fractions are heavily contaminated, detailed investigation of biomarkers in these rock extracts and comparison with biomarkers in the oil-based mud has revealed that, while there are hopane and sterane biomarkers in the mud, there are also a discrete set of biomarkers that are indigenous to the rocks. These include oleanane, bicadinanes, taraxastane and other higher-plant-derived triterpanes. The presence of these compounds in environments that range from bathyal to marginal marine and even to lacustrine, shows the extent of reworking of terrestrial material into aquatic settings in this region during the Paleogene and Neogene and provides further evidence of a predominance of terrestrial material, even in deep-marine settings, with little ‘in-situ’ material noted. These findings have important implications for the use of biomarkers as indicators of palaeoenvironment in both source rocks and oils.

The article discusses an approach to smart automation regarding system and technology, human experience, and business process. Topics include the three stages of automation such as the focus on removing paper-based records, the internal process workflows, and end users, various factors that trigger smart automation including the use of data-based intelligence, machine learning (ML), and adaptive programming model, and the human factors in the design of smart automation.

The direct hydroxylation of 2-arylpyridines and 2-arylbenzothiazoles via the merger of organic photoredox and metal catalysis is reported where 4CzIPN is used as the visible-light photocatalyst and Pd(OAc)2as the metal catalyst. This method has been employed to synthesize organic molecules exhibiting excited-state intramolecular proton transfer properties for generating tunable luminescence responses.

Roads are becoming increasingly congested due to urbanization and the increased use of private vehicles. As a result, emergency vehicles like ambulances, police cars, and fire trucks get stuck in traffic and take longer to get where they're going, which may cause risk, damage to property, and losing valuable lives. The acoustic-based pre-emption technology uses the EV's siren to alert oncoming cars. Therefore, acoustic reflection from a building or other large container vehicle might cause a fall. This paper implements a vehicle-to-infrastructure (V2I) communication system that anticipates traffic signals using Global Positioning System (GPS) and Dedicated Short Range Communication (DSRC). Line of sight (LOS) is not required when choosing the desired range of DSRC communication, and the traffic signal unit receives pre-emption messages anytime an emergency vehicle is nearby. Thus, these messages cause the traffic light to turn green for the emergency vehicle instead of operating normally. As a result, this type of system necessitates two hardware modules, one at each vehicle On-Board-Unit (OBU) and one at each intersection Road-Side-Unit (RSU), as well as the Decision Support System i.e., Traffic Management Controller (TMC). In the hardware OBU and RSU, the IMX-6 Processor, GPS Module, and DSRC transmitter and receivers are used. The Emergency Vehicle (EV) equipped with the OBU transmits requests to the intersection unit, which is fully autonomous and can be employed as a component of the Intelligent Transportation System (ITS), negating the need for a driver in this method.

The adsorption of polyaromatic hydrocarbons (PAHs) on metallic substrates is of interest in the field of optoelectronics, due to the possibility of designing complex materials with tunable properties through surface functionalization with organic molecules. Much of the modeling research in this field has focused on perfectly symmetrical (pristine) substrates. There is limited information on the effect of substrate irregularities, such as adatoms, on the binding of PAHs onto substrates. Here, we examine how the presence of substrate-bound adatoms affects the binding of coronene and hexahelicene monomers and dimers on Au(111) and Cu(111) substrates, using a density functional theory approach. We found that helicene monomers were more effectively able to adapt to the presence of the adatoms than coronene by coiling around the adatoms. Whereas upon adsorption on a pristine (111) surface, coronene can establish significantly stronger dispersive interactions than helicenes, adatom defects reverse the trend. For helicenes, the extent of flattening near the surface and molecular coiling are strongly influenced by the size of the defect, as a result of the interplay between the molecule’s drive to maximize overlap with the underlying surface and the enhanced reactivity of the low-coordinated adatoms.

The article discusses the art and science of conversational business application development. Topics include the types of conversational business applications, the distinctive characteristics that define them, the business benefits of adopting them, and the channels that connect users with the applications, namely intelligent assistants, messaging platforms and standalone applications.

The rate of liver transplantation is increasing among the elderly population; however, data is limited on the post-liver transplantation outcomes in patients ≥70 years. Given the scarcity in liver allograft resources, a meta-analysis on the outcomes of liver transplantation in patients ≥70 years is warranted.

Fluoxetine is a commonly prescribed antidepressant agent in psychotherapy. A rapid, selective and sensitive LC-MS/MS method was developed and validated for simultaneous estimation of fluoxetine and its metabolite nor-fluoxetine in rabbit and human plasma. The assay was linear over the concentration range of 0.048–100 ng mL−1with a lower limit of detection of 32 pg mL−1(0.032 ng mL−1) for both fluoxetine and nor-fluoxetine. Separation and detection of analytes were achieved on a reversed phase Waters Symmetry Shield™ C18column, with an isocratic mobile phase consisting of methanol and 0.5% formic acid (80 : 20, v/v) at a flow rate of 0.75 mL min−1. A turnover rate of 2.5 min per sample enables the high-throughput bioanalysis of fluoxetine. An automated solid phase extraction method was employed for efficient extraction of analytes from the matrix. Thereafter, analytes were monitored by using MS/MS with an electrospray ionization source in positive multiple reaction monitoring mode. The method was successfully applied to in vivopharmacokinetic studies in rabbit and in vitroprotein binding studies in human plasma. Due to high sensitivity and low requirement of sample volume, the method could be applicable for preclinical and clinical applications such as therapeutic drug monitoring in special population (children and geriatric patients) using only 0.03 mL of plasma.

Natural products have been used traditionally for the treatment and prevention of diseases. Diapocynin is the analogue of the naturally occurring apocynin, a well-known constituent of Picrorhiza kurroa. It has antioxidant properties and also is effective in neuro-inflammatory diseases. To investigate in vitroand in vivopharmacokinetics of diapocynin, a simple and sensitive method was developed and validated in rat plasma using high-performance liquid chromatography coupled with a mass spectrometer (LC-MS/MS). The developed and validated method requires low volume of the plasma (25 μL). The analytes were extracted by a simple protein precipitation method using acetonitrile. Chromatography resolution = nwas achieved by using a Thermo Accucore C18(5 μ, 4.6 × 150 mm) column using a mobile phase of acetonitrile and ammonium acetate buffer (10 mM, pH 4.0). The present method was successfully applied for in vitroclearance (using rat liver microsomes) and in vivooral pharmacokinetic studies in the Sprague Dawleyrats.

A simple and highly efficient protocol has been developed for in vitro regeneration of Pterocarpus marsupiumusing immature zygotic embryo (IZE) as explant. The highest frequency of shoot regeneration (93.8%) was obtained on Murashige and Skoog (MS) medium supplemented with 3.0 mg·L−16-benzylaminopurine (BA) and 0.5 mg·L−1indole-3-acetic acid (IAA), wherein maximum of 17.3 ± 0.9 shoots per explant was induced. When these cultures were sub-cultured on MS medium supplemented with 1.0 mg·L−1BA, more shoots (27.2 ± 1.1) with an average shoot length of 4.5 cm were observed. The highest rooting (70.8%) and maximum number of roots (3.2 ± 0.3) per shoot were obtained when shoots were dipped in 3.0 mg·L−1indol-3-butyric acid (IBA) solution for 24 hours and further cultured on half-strength MS medium. Plantlets obtained in vitro were transferred to the field after being hardened with a 74% survival rate. Analysis of regenerated plantlets using inter-simple sequence repeat (ISSR) markers confirmed that there was no genetic variability. All ISSR banding profiles from regenerated plantlets were monomorphic and similar to those of the mother plant. This protocol might be helpful for the mass multiplication and in vitro conservation of P. marsupium.

AbstractNeuromyelitis optica, also known as Devic's disease, is a rare autoimmune disorder in which a patient's immune system affects the optic nerves and the spinal cord, leading to loss of vision and spinal cord dysfunction. We present our experience with a 38-year-old female who presented to our facility with complaints of intractable nausea and vomiting. After extensive evaluation, she was found to have neuromyelitis optica. Her symptoms completely resolved following institution of appropriate therapy. She made a significant recovery and has since been placed on chronic immunosuppressive therapy. Through this article we hope to bring attention to a significant cause of intractable nausea and vomiting that may often be forgotten in general medicine or gastroenterology services.© 2013 S. Karger AG, Basel