Phosphorylation of Orc6 During Mitosis Regulates DNA Replication and Ribosome Biogenesis.

The human Origin Recognition Complex (ORC) is required not only for the initiation of DNA replication, but is also implicated in diverse cellular functions, including chromatin organization, centrosome biology, and cytokinesis. The smallest subunit of ORC, Orc6, is poorly conserved amongst eukaryotes. Recent studies from our laboratory have suggested that human Orc6 is not required for replication licensing, but is needed for S-phase progression. Further, ATR-dependent phosphorylation of Orc6 at T229 is implicated in DNA damage response during S-phase. In this study, we demonstrate that the CDK-dependent phosphorylation of Orc6 at T195 occurs during mitosis. While the phosphorylation at T195 does not seem to be required to exit mitosis, cells expressing the phosphomimetic T195E mutant of Orc6 impede S-phase progression. Moreover, the phosphorylated form of Orc6 associates with ORC more robustly, and Orc6 shows enhanced association with the ORC outside of G1, supporting the view that Orc6 may prevent the role of Orc1-5 in licensing outside of G1. Finally, Orc6 and the phosphorylated Orc6 localize to the nucleolar organizing centers and regulate ribosome biogenesis. Our results suggest that phosphorylated Orc6 at T195 prevents replication.

Whole genome sequence-based molecular characterization of blood isolates of carbapenem-resistant Enterobacter cloacae complex from ICU patients in Kolkata, India, during 2017-2022: emergence of phylogenetically heterogeneous Enterobacter hormaechei subsp. xiangfangensis.

Blood-borne infections caused by the carbapenem-resistant Enterobacter cloacae complex (CR-ECC) are major public threats with respect to the challenges encountered during treatment. This study describes the whole genome sequencing-based molecular characteristics of blood isolates (n = 70) of CR-ECC from patients admitted to the intensive care unit of tertiary care hospitals in Kolkata, India, during 2017-2022 with respect to species identification, antimicrobial resistance (AMR) profiling, mechanism of drug resistance, and molecular subtypes. Vitek2 MALDI and species-specific PCR identified Enterobacter hormaechei subsp. xiangfangensis (47.14%) as the emerging CR-ECC subspecies in Kolkata. The predominating carbapenemase and extended-spectrum ß-lactamase genes found were blaNDM-1 (51.42%) and blaCTX-M-15 (27%), respectively. Besides, blaNDM-4, blaNDM-5, blaNDM-7, blaCMH-3, blaSFO-1, blaOXA-181, blaOXA-232, blaKPC-3, and blaDHA-7 genes were also detected, which were not previously reported from India. A multitude of Class 1 integrons (including In180, In4874, In4887, and In4888, which were novel) and plasmid replicon types (IncFIB, IncFII, IncX3, IncHI1-HI2, IncC, and IncR) involved in AMR dissemination were identified. Reverse transcription-PCR and western blot revealed that carbapenem resistance in non-carbapenemase-producing CR-ECC isolates was contributed by elevated levels of ampC, overexpression of acrAB, and loss of ompF. A total of 30 distinct sequence types (STs) were ascertained by multi-locus sequence typing; of which, ST2011, ST2018, ST2055, ST2721, and ST2722 were novel STs. Pulsed-field gel electrophoresis analysis showed heterogeneity (69 pulsotypes with a similarity coefficient of 48.40%) among the circulating isolates, suggesting multiple reservoirs of infections in humans. Phylogenetically and genetically diverse CR-ECC with multiple AMR mechanisms mandates close monitoring of nosocomial infections caused by these isolates to forestall the transmission and dissemination of AMR.IMPORTANCEThe emergence and extensive dissemination of the carbapenem-resistant Enterobacter cloacae complex (CR-ECC) have positioned it as a critical nosocomial global pathogen. The dearth of a comprehensive molecular study pertaining to CR-ECC necessitated this study, which is the first of its kind from India. Characterization of blood isolates of CR-ECC over the last 6 years revealed Enterobacter hormaechei subsp. xiangfangensis as the most prevalent subsp., exhibiting resistance to almost all antibiotics currently in use and harboring diverse transmissible carbapenemase genes. Besides the predominating blaNDM-1 and blaCTX-M-15, we document diverse carbapenemase and AmpC genes, such as blaNDM-4, blaNDM-7, blaOXA-181, blaOXA-232, blaKPC-3, blaCMH-3, blaSFO-1, and blaDHA-7, in CR-ECC, which were not previously reported from India. Furthermore, novel integrons and sequence types were identified. Our findings emphasize the need for strengthened vigilance for molecular epidemiological surveillance of CR-ECC due to the presence of epidemic clones with a phylogenetically diverse and wide array of antimicrobial resistance genes in vulnerable populations.

Enhancement of Spontaneous Photon Emission in Inverse Photoemission Transitions in Semiconductor Quantum Dots.

Inverse photoemission (IPE) is a radiative electron capture process where an electron is transiently captured in the conduction band (CB) followed by intraband de-excitation and spontaneous photon emission. IPE in quantum dots (QDs) bypasses optical selection rules for populating the CB and provides insights into the capacity for electron capture in the CB, the propensity for spontaneous photon emission, intraband transition energies where both initial and final states are in the CB, and the generation of photons with frequencies lower than the bandgap. Here, we demonstrate using time-dependent perturbation theory that judicious application of electric fields can significantly enhance the IPE transition in QDs. For a series of CdSe, CdS, PbSe, and PbS QDs, we present evidence of field-induced enhancement of IPE intensities (188% for Cd54Se54), field-dependent control of emitted photon frequencies (Δω = 0.73 eV for Cd54Se54), and enhancement of light-matter interaction using directed Stark fields (103% for Cd54Se54).

An Affordable Topography-Based Protocol for Assigning a Residue's Character on a Hydropathy (PARCH) Scale.

The hydropathy of proteins or quantitative assessment of protein-water interactions has been a topic of interest for decades. Most hydropathy scales use a residue-based or atom-based approach to assign fixed numerical values to the 20 amino acids and categorize them as hydrophilic, hydroneutral, or hydrophobic. These scales overlook the protein's nanoscale topography, such as bumps, crevices, cavities, clefts, pockets, and channels, in calculating the hydropathy of the residues. Some recent studies have included protein topography in determining hydrophobic patches on protein surfaces, but these methods do not provide a hydropathy scale. To overcome the limitations in the existing methods, we have developed a Protocol for Assigning a Residue's Character on the Hydropathy (PARCH) scale that adopts a holistic approach to assigning the hydropathy of a residue. The parch scale evaluates the collective response of the water molecules in the protein's first hydration shell to increasing temperatures. We performed the parch analysis of a set of well-studied proteins that include the following─enzymes, immune proteins, and integral membrane proteins, as well as fungal and virus capsid proteins. Since the parch scale evaluates every residue based on its location, a residue may have very different parch values inside a crevice versus a surface bump. Thus, a residue can have a range of parch values (or hydropathies) dictated by the local geometry. The parch scale calculations are computationally inexpensive and can compare hydropathies of different proteins. The parch analysis can affordably and reliably aid in designing nanostructured surfaces, identifying hydrophilic and hydrophobic patches, and drug discovery.

Inserting an "atomic trap" for directional dopant migration in core/multi-shell quantum dots.

Diffusion of atoms or ions in solid crystalline lattice is crucial in many areas of solid-state technology. However, controlling ion diffusion and migration is challenging in nanoscale lattices. In this work, we intentionally insert a CdZnS alloyed interface layer, with small cationic size mismatch with Mn(ii) dopant ions, as an "atomic trap" to facilitate directional (outward and inward) dopant migration inside core/multi-shell quantum dots (QDs) to reduce the strain from the larger cationic mismatch between dopants and host sites. Furthermore, it was found that the initial doping site/environment is critical for efficient dopant trapping and migration. Specifically, a larger Cd(ii) substitutional site (92 pm) for the Mn(ii) dopant (80 pm), with larger local lattice distortion, allows for efficient atomic trapping and dopant migration; while Mn(ii) dopant ions can be very stable with no significant migration when occupying a smaller Zn(ii) substitutional site (74 pm). Density functional theory calculations revealed a higher energy barrier for a Mn(ii) dopant hopping from the smaller Zn substitutional tetrahedral (Td) site as compared to a larger Cd substitutional Td site. The controlled dopant migration by "atomic trapping" inside QDs provides a new way to fine tune the properties of doped nanomaterials.

Interfacial B-Site Ion Diffusion in All-Inorganic Core/Shell Perovskite Nanocrystals.

All-inorganic metal halide perovskites (ABX3, X = Cl, Br, or I) show great potential for the fabrication of optoelectronic devices, but the toxicity and instability of lead-based perovskites limit their applications. Shell passivation with a more stable lead-free perovskite is a promising strategy to isolate unstable components from the environment as well as a feasible way to tune the optical properties. However, it is challenging to grow core/shell perovskite nanocrystals (NCs) due to the soft ionic nature of the perovskite lattice. In this work, we developed a facile method to grow a lead-free CsMnCl3 shell on the surface of CsPbCl3 NCs to form CsPbCl3/CsMnCl3 core/shell NCs with enhanced environmental stability and improved photoluminescence (PL) quantum yields (QYs). More importantly, the resulting core/shell perovskite NCs have color-tunable PL due to B-site ion diffusion at the interface of the core/shell NCs. Specifically, B-site Mn diffusion from the CsMnCl3 shell to the CsPbCl3 core leads to a Mn-doped CsPbCl3 core (i.e., Mn:CsPbCl3), which can turn on the Mn PL at around 600 nm. The ratio of Mn PL and host CsPbCl3 PL is highly tunable as a function of the thermal annealing time of the CsPbCl3/CsMnCl3 core/shell NCs. While the halide anion exchange for all-inorganic metal halide perovskites has been well-developed for band-gap-engineered materials, interfacial B-site diffusion in core/shell perovskite NCs is a promising approach for both tunable optical properties and enhanced environmental stability.

In-silico study of type 'B' condylar head fractures and evaluating the influence of two positional screw distance in two-screw osteosynthesis construct.

Clinical fixation screws are common in clinical practices to fix mandibular condyle fractures. Evidence suggests significance of 'working length' that is, distance between proximal and distal fixation screws in proximity to the fracture in orthopaedic implant design. In pursuit of stable implant-bone construct, this study aims to investigate the biomechanical performance of each configuration considered in the study and provide an optimal working length between the screws for clinical reference. Finite element models of virtually designed broken condyle as type 'B' were simulated and analysed in ANSYS Workbench. Screws are implanted according to previous literature at five varied distances 'd' maintaining five different ratios with the fracture length 'D'. Based on a literature review, boundary conditions, muscle traction forces and non-linear contacts were assigned to obtain precise results. Each case is considered an individual configuration and von Mises distribution, microstrain in bone, screw-bone interface micromotion and fracture dislocation were evaluated for all these configurations. Stress-shielding phenomenon is observed for maximum von Mises stresses in bone. Microstrain concentration was significant in cancellous bone in the vicinity of the screw around the fracture line. Configurations were compared based on the stress-strain along with micromotion to support the required amount of osseointegration between implant and bone. Presented data from all five conditions supported the assumption that under physiological loading conditions, the D3 configuration provided stability for fracture healing. Further research on screw shapes, diameters and material properties, or investigating the direction of forces within the screws could provide further insight into this topic.

3D Printing of Ti-6Al-4V-Based Porous-Channel Dental Implants: Computational, Biomechanical, and Cytocompatibility Analyses.

Objective: Loosening of dental implants due to resorption of the surrounding bone is one of the challenging clinical complications in prosthetic dentistry. Generally, stiffness mismatch between an implant and its surrounding bone is one of the major factors. In order to prevent such clinical consequences, it is essential to develop implants with customized stiffness. The present study investigates the computational and experimental biomechanical responses together with cytocompatibility studies of three-dimensional (3D)-printed Ti-6Al-4V-based porous dental implants with varied stiffness properties. Methods: Additive manufacturing (direct metal laser sintering, DMLS) was utilized to create Ti-6Al-4V implants having distinct porosities and pore sizes (650 and 1000 µm), along with a nonporous (solid) implant. To validate the compression testing of the constructed implants and to probe their biomechanical response, finite element models were employed. The cytocompatibility of the implants was assessed using MG-63 cells, in vitro. Results: Both X-ray microcomputed tomography (µ-CT) and scanning electron microscopy (SEM) studies illustrated the ability of DMLS to produce implants with the designed porosities. Biomechanical analysis results revealed that the porous implants had less stiffness and were suitable for providing the appropriate peri-implant bone strain. Although all of the manufactured implants demonstrated cell adhesion and proliferation, the porous implants in particular supported better bone cell growth and extracellular matrix deposition. Conclusions: 3D-printed porous implants showed tunable stiffness properties with clinical translational potential.

DNA Damage-Induced, S-Phase Specific Phosphorylation of Orc6 is Critical for the Maintenance of Genome Stability.

The smallest subunit of the human Origin Recognition Complex, hOrc6, is required for DNA replication progression and plays an important role in mismatch repair (MMR) during S-phase. However, the molecular details of how hOrc6 regulates DNA replication and DNA damage response remain to be elucidated. Orc6 levels are elevated upon specific types of genotoxic stress, and it is phosphorylated at Thr229, predominantly during S-phase, in response to oxidative stress. Many repair pathways, including MMR, mediate oxidative DNA damage repair. Defects in MMR are linked to Lynch syndrome, predisposing patients to many cancers, including colorectal cancer. Orc6 levels are known to be elevated in colorectal cancers. Interestingly, tumor cells show reduced hOrc6-Thr229 phosphorylation compared to adjacent normal mucosa. Further, elevated expression of wild-type and the phospho-dead forms of Orc6 results in increased tumorigenicity, implying that in the absence of this "checkpoint" signal, cells proliferate unabated. Based on these results, we propose that DNA-damage-induced hOrc6-pThr229 phosphorylation during S-phase facilitates ATR signaling in the S-phase, halts fork progression, and enables assembly of repair factors to mediate efficient repair to prevent tumorigenesis. Our study provides novel insights into how hOrc6 regulates genome stability.

An adaptive fuzzy logic control technique for LVRT enhancement of a grid-integrated DFIG-based wind energy conversion system.

The fast improvement of wind energy conversion technology with optimization algorithms has recently received a lot of attention. However, their slow convergence speed, huge computational load, and low efficiency are the main drawbacks and to improve these disadvantages, a new adaptive fuzzy logic controller strategy is proposed to enhance the low voltage ride-through of the grid-connected doubly fed induction generator during severe grid faults. The rotor side converter and the grid side converter are controlled using an adaptive fuzzy logic controller topology under cascaded structure to improve the performance. The novel application of the 'generalized variable step-size diffusion continuous mixed p-norm' adaptive filtering algorithm is proposed to modify the calibrating factors of the fuzzy logic controllers at a rapid convergence speed with low normalized misalignment error. The proposed adaptive algorithm-based fuzzy logic controller has a better low voltage ride-through improvement capability than that of using the particle swarm optimization-based proportional-integral controller during severe grid disturbances. The convergence speed of the proposed adaptive filtering algorithm is compared to that of existing algorithms such as least mean fourth, least mean square, and continue mixed p-norm algorithms. In addition, a comparison is also made with different common optimization methods. The field-programmable gate array-based real-time experimental results are presented to validate the proposed adaptive control topology.

Probing the Influence of Hybrid Thread Design on Biomechanical Response of Dental Implants: Finite Element Study and Experimental Validation.

This study aimed to perform quantitative biomechanical analysis for probing the effect of varying thread shapes in an implant for improved primary stability in prosthodontics surgery. Dental implants were designed with square (SQR), buttress (BUT), and triangular (TRI) thread shapes or their combinations. Cone-beam computed tomography images of mandible molar zones in human subjects belonging to three age groups were used for virtual implantation of the designed implants, to quantify patient-specific peri-implant bone microstrain, using finite element analyses. The in silico analyses were carried out considering frictional contact to simulate immediate loading with a static masticatory force of 200 N. To validate computational biomechanics results, compression tests were performed on three-dimensional printed implants having the investigated thread architectures. Bone/implant contact areas were also quantitatively assessed. It was observed that, bone/implant contact was maximum for SQR implants followed by BUT and TRI implants. For all the cases, peak microstrain was recorded in the cervical cortical bone. The combination of different thread shapes in the middle or in the apical part (or both) was demonstrated to improve peri-implant microstrain, particularly for BUT and TRI. Considering 1500-2000 microstrain generates in the peri-implant bone during regular physiological functioning, BUT-SQR, BUT-TRI-SQR, TRI-SQR-BUT, SQR, and SQR-BUT-TRI design concepts were suitable for younger; BUT-TRI-SQR, BUT-SQR-TRI, TRI-SQR-BUT, SQR-BUT, SQR-TRI for middle-aged, and BUT-TRI-SQR, BUT-SQR-TRI, TRI-BUT-SQR, SQR, and SQR-TRI for the older group of human patients.

Investigation of Ionization Potential in Quantum Dots Using the Stratified Stochastic Enumeration of Molecular Orbitals Method.

The overarching goal of this work is to investigate the size-dependent characteristics of the ionization potential of PbS and CdS quantum dots. The ionization potentials of quantum dots provide critical information about the energies of occupied states, which can then be used to quantify the electron-removal characteristics of quantum dots. The energy of the highest-occupied molecular orbital is used to understand electron-transfer processes when invesigating the energy-level alignment between quantum dots and electron-accepting ligands. Ionization potential is also important for investigating and interpreting electron-detachment processes induced by light (photoelectron spectra), external voltage (chemiresistance), and collision with other electrons (impact ionization). Accurate first-principles calculations of ionization potential continue to be challenging because of the computational cost associated with the construction of the frequency-dependent self-energy operator and the numerical solution of the associated Dyson equation. The computational cost becomes prohibitive as the system size increases because of the large number of 2particle-1hole (2p1h) and 1particle-2hole (1p2h) terms needed for the calculation. In this work, we present the Stratified Stochastic Enumeration of Molecular Orbitals (SSE-MO) method for efficient construction of the self-energy operator. The SSE-MO method is a real-space method and the central strategy of this method is to use stochastically enumerated sampling of molecular orbitals and molecular-orbital indices for the construction of the 2p1h and 1p2h terms. This is achieved by first constructing a composite MO-index Cartesian coordinate space followed by transformation of the frequency-dependent self-energy operator to this composite space. The evaluation of both the real and imaginary components of the self-energy operator is performed using a stratified Monte Carlo technique. The SSE-MO method was used to calculate the ionization potentials and the frequency-dependent spectral functions for a series of PbS and CdS quantum dots by solving the Dyson equation using both single-shot and iterative procedures. The ionization potentials for both PbS and CdS quantum dots were found to decrease with increasing dot size. Analysis of the frequency-dependent spectral functions revealed that for PbS quantum dots the intermediate dot size exhibited a longer relative lifetime whereas in CdS the smallest dot size had the longest relative lifetime. The results from these calculations demonstrate the efficacy of the SSE-MO method for calculating accurate ionization potentials and spectral functions of chemical systems.

Design of patient specific basal dental implant using Finite Element method and Artificial Neural Network technique.

The bone conditions of mandibular bone vary from patient to patient, and as a result, a patient-specific dental implant needs to be designed. The basal dental implant is implanted in the cortical region of the bone since the top surface of the bone narrows down because of aging. Taguchi designs of experiments technique are used in which 25 optimum solid models of basal dental implants are modeled with variable geometrical parameters, viz. thread length, diameter, and pitch. In the solid models the implants are placed in the cortical part of the 3D models of cadaveric mandibles, that are prepared from CT data using image processing software. Patient-specific bone conditions are varied according to the strong, weak, and normal basal bone. A compressive force of 200 N is applied on the top surface of these implants and using finite element analysis software, the microstrain on the peri-implant bone ranges from 1000 to 4000 depending on the various bone conditions. According to the finite element data, it can be concluded that weak bone microstrain is comparatively high compared with normal and strong bone conditions. A surrogate artificial neural network model is prepared from the finite element analysis data. Surrogate model assisted genetic algorithm is used to find the optimum patient-specific basal dental implant for a better osseointegration-friendly mechanical environment.

Influence of implant parameters on biomechanical stability of TMJ replacement: A finite element analysis.

The articular disc reduces the stress distribution from the mandible to fossa. In total temporomandibular joint (TMJ) replacement, the implant is required to reduce the stress on fossa implant. Current studies lack standard and optimized parameters for the cylindrical dome on Christensen TMJ implant collar. This study briefed a novel TMJ implant head design and investigates the biomechanical behaviour by considering the articular disc. The radius of the head was varied with the height of the cylinder height to obtain the design of the experiment and the stress distribution was compared with an intact mandible-articular disc model by considering the viscoelastic property of the TMJ disc. The model was simulated at three different angles: 20°, 0° and -20° in the mediolateral direction to simulate the manducation. FEA analysis showed high stresses at the circular heads, and high strength is achieved with increased implant cylinder length and diameter. The results also showed a stress reduction of 50% on the fossa from the mandible. Hence, the newly designed head and suggested modifications may be used as a reference for further clinical improvement of Christensen TMJ as well as other TMJ implants.

Probing combinational influence of design variables on bone biomechanical response around dental implant-supported fixed prosthesis.

This study aimed to understand the effect of physiological and dental implant-related parameter variations on the osseointegration for an implant-supported fixed prosthesis. Eight design factors were considered (implant shape, diameter, and length; thread pitch, depth, and profile; cantilever [CL] length and implant-loading protocol). Total 36 implantation scenarios were simulated using finite element method based on Taguchi L36 orthogonal array. Three patient-specific bone conditions were also simulated by scaling the density and Young's modulus of a mandible sample to mimic weak, normal, and strong bones. Taguchi method was employed to determine the significance of each design factor in controlling the peri-implant cortical bone microstrain. For normal bone condition, CL length had the maximum contribution (28%) followed by implant diameter (18%), thread pitch (14%), implant length (8%), and thread profile (5%). For strong bone condition, CL and implant diameter had equal contribution (32%) followed by thread pitch (7%) and implant length (5%). For weak bone condition, implant diameter had the highest contribution (31%) followed by CL length (30%), thread pitch (11%) and implant length (8%). The presence of distal CL in dental framework was found to be the most influential design factor, which can cause high strain in the cervical cortical bone. It was seen that implant diameter had more effect compared to implant length toward peri-implant bone biomechanical response. Implant-loading time had no significant effect towards peri-implant bone biomechanical response, signifying immediate loading is possible with sufficient mechanical retention.

Orc6 is a component of the replication fork and enables efficient mismatch repair.

In eukaryotes, the origin recognition complex (ORC) is required for the initiation of DNA replication. The smallest subunit of ORC, Orc6, is essential for prereplication complex (pre-RC) assembly and cell viability in yeast and for cytokinesis in metazoans. However, unlike other ORC components, the role of human Orc6 in replication remains to be resolved. Here, we identify an unexpected role for hOrc6, which is to promote S-phase progression after pre-RC assembly and DNA damage response. Orc6 localizes at the replication fork and is an accessory factor of the mismatch repair (MMR) complex. In response to oxidative damage during S phase, often repaired by MMR, Orc6 facilitates MMR complex assembly and activity, without which the checkpoint signaling is abrogated. Mechanistically, Orc6 directly binds to MutSα and enhances the chromatin-association of MutLα, thus enabling efficient MMR. Based on this, we conclude that hOrc6 plays a fundamental role in genome surveillance during S phase.

Asymmetric response of the Indian summer monsoon to positive and negative phases of major tropical climate patterns.

The existing theories for the tropical teleconnections to Indian summer monsoon (ISM) are diverse in approaches. As a result, it is impossible to quantify the relative impacts of different tropical climate patterns on ISM, complying with a single physical mechanism. Here, we show that tropical teleconnections to ISM can be explained through net moisture convergence driven by surface pressure (Ps) gradients surrounding the Indian region. The positive and negative phases of major tropical climate patterns modulate these pressure gradients asymmetrically in the zonal and/or meridional directions leading to asymmetric changes in moisture convergence and ISM rainfall (ISMR). Stronger El Nino droughts than La Nina floods are due to greater decreased eastward moisture flux over the Arabian Sea during El Nino than the corresponding increase during La Nina driven by proportionate meridional Ps gradients. While the equatorial Atlantic Ocean's sea surface temperature in boreal summer and El Nino Southern Oscillation in the preceding winter changes ISMR significantly, moisture convergence anomalies driven by the Indian Ocean Dipole were insignificant. Moreover, while ISMR extremes during ENSO are due to asymmetric changes in zonal and meridional gradients in Ps, non-ENSO ISMR extremes arise due to the zonal gradient in zonally symmetric Ps anomalies.

Assessment of Jaw Bone Quality for Designing Patient-Specific Dental Implant Using Computed Tomography Data.

It is essential to assess bone density among mandible teeth as well as among patients and also to observe the variation in all mechanical parameters of the bone for accurate design of patient-specific dental implants. This information helps in the design of implants to create a more osseointegration-friendly environment at the bone adjacent to the implant. For this study, 40 patients were chosen irrespective of age, sex, and bone density. Hounsfield Units were calculated using cone beam computed tomography data. Seven teeth were studied: central incisor, lateral incisor, canine, first premolar, second premolar, first molar, and second molar. A total of 12 arbitrary points were chosen in both buccal and lingual sides which were further divided into external and internal. From the analysis, it was observed that the bone density of the central incisor and that of the canine is greater than that of the molars.

Characterization of zinc solubilization potential of arsenic tolerant Burkholderia spp. isolated from rice rhizospheric soil.

In this study, experiments were conducted to isolate, characterize, and evaluate rice rhizosphere bacteria for their arsenic (As) tolerance ability and zinc (Zn) solubilization potential in culture media and soil. Among 20 bacterial isolates recovered, six were found to solubilize inorganic Zn salt(s) efficiently under in vitro culture conditions. 16S rRNA gene sequence-based phylogenetic analysis indicated the affiliation of efficient Zn solubilizing bacteria (ZSB) to Burkholderia vietnamiensis and Burkholderia seminalis. Zinc solubilizing efficiency (ZSE) of the bacteria varied with the concentrations and types of Zn salts used in the experiments. Increasing trend in ZSE of the bacteria was noticed when the percentage of ZnO increased from 0.1 to 0.5 but the same decreased at 1.0%. Increased Zn solubilization was noticed when bacteria were incubated with lower concentration of Zn3(PO4)2 and ZnCO3. In general, Zn solubilization increased with increasing incubation time in lower volume medium, while some isolates failed to solubilize one or more tested Zn salts. However, enriched concentrated cells of the ZSB in glucose amended medium with 0.5% ZnO showed an increasing trend of Zn solubilization with time and were able to solubilize more than 300 mg/L Zn. This increased rate of Zn release by the ZSB was attributed to marked decline in pH that might be due to the enhanced gluconic acid production from glucose. As evident from the decreased ZSE of the bacteria in the presence of As(V) in particular, it seems arsenic imparts a negative effect on Zn solubilization. The ZSB were also able to increase the rate of Zn release in soil. A microcosm-based soil incubation study amending the enriched bacteria and 0.5% ZnO in soil showed an elevated level of both water-soluble and available Zn compared to un-inoculated control. During Zn solubilization in microcosms, viable cells in terms of colony-forming unit (CFU) declined by the same order of magnitude both in the presence and absence of ZnO that might be due to the nutrients limiting condition aroused during the incubation period rather than Zn toxicity. The bacteria in this study also exhibited plant growth promoting traits, such as growth in nitrogen-free medium, production of indole acetic acid (IAA), and solubilization of potassium and phosphate. Our findings suggested that Burkholderia spp. could be the potential candidates for enhancing Zn dissolution in the soil that might reduce the rate of inorganic Zn fertilization in agricultural soil.

The S-phase-induced lncRNA SUNO1 promotes cell proliferation by controlling YAP1/Hippo signaling pathway.

Cell cycle is a cellular process that is subject to stringent control. In contrast to the wealth of knowledge of proteins controlling the cell cycle, very little is known about the molecular role of lncRNAs (long noncoding RNAs) in cell-cycle progression. By performing genome-wide transcriptome analyses in cell-cycle-synchronized cells, we observed cell-cycle phase-specific induction of >2000 lncRNAs. Further, we demonstrate that an S-phase-upregulated lncRNA, SUNO1, facilitates cell-cycle progression by promoting YAP1-mediated gene expression. SUNO1 facilitates the cell-cycle-specific transcription of WTIP, a positive regulator of YAP1, by promoting the co-activator, DDX5-mediated stabilization of RNA polymerase II on chromatin. Finally, elevated SUNO1 levels are associated with poor cancer prognosis and tumorigenicity, implying its pro-survival role. Thus, we demonstrate the role of a S-phase up-regulated lncRNA in cell-cycle progression via modulating the expression of genes controlling cell proliferation.