Rediscovery and systematics of Rhinophis fergusonianus Boulenger, 1896 (Serpentes: Uropeltidae) from Indias Western Ghats.

The shieldtail snake Rhinophis fergusonianus Boulenger, 1896 was previously known only from the holotype specimen collected approximately 130 years ago from an imprecise Indian locality (Cardamom Hills). We report the rediscovery of this species from four localities, from low-elevation hills on both sides of the Palghat Gap in the southern part of the Western Ghats of peninsular India. We document new specimens of R. fergusonianus and provide a reassessment of the systematics of the species based on external morphology and DNA-sequence data. We also provide a revised key to the identification of Indian species of Rhinophis.

Morphological and molecular differences in two closely related Calotes Cuvier, 1817 (Squamata: Agamidae: Draconinae) with the first record of Calotes medogensis Zhao & Li, 1984 from India.

We studied the morphological and genetic differences within Calotes jerdoni, a widespread species across northeast India. Our results suggest the presence of two distinct species in this region, one being Calotes jerdoni and the other being Calotes medogensis, which we report for the first time from India. We designate a lectotype for Calotes jerdoni and provided extended description based on freshly collected materials. Previously undetermined diagnostic characters were identified and are discussed here in detail. The aforementioned species show an interspecific pairwise genetic divergence of 13-14% in the ND2 mitochondrial gene.

Rediscovery and systematics of the rarely encountered Blue-bellied kukri snake (Oligodon melaneus Wall, 1909) from Assam, India.

We report the rediscovery of Oligodon melaneus 112 years after its original description and document the third, and only non-type, specimen for the species. The new specimen was found 267 km east of the type locality (Tindharia, West Bengal state) from Assam state, India. We designate a lectotype for the species, and provide an extended description of a freshly collected male specimen. Phylogenetic analyses of 16s and cytb mitochondrial genes provide support for O. melaneus being closely related to the widespread South Asian endemic O. arnensis.

On the identity, nomenclatural status and authorship of Coluber monticolus Cantor, 1839 (Reptilia: Serpentes).

Currently, Coluber monticolus Cantor is considered a junior synonym of the Common kukri snake, Oligodon arnensis Shaw. In this work, we analyzed long time disregarded, unpublished original drawings and manuscripts concerning South Asian snakes. Additionally we recall the hitherto little-noticed contact and exchange between B. H. Hodgson and T. E. Cantor. We correct erroneous assumptions regarding the authorship and identity of C. monticolus and, in accordance with Art. 23.9 of the "Code" (ICZN 1999), we declare Dipsas multifasciata Blyth a nomen protectum with priority over Coluber monticolus Hodgson in Cantor (nomen oblitum).

On the status and validity of the recently described Raorchestes kollimalai Gowande, Ganesh amp; Mirza 2020.

A recent addition to the Indian herpetofauna is Roarchestes kollimalai Gowande, Ganesh Mirza 2020, a bush frog species, described based on a type series of three specimens from the Kolli hills in the lesser-known Eastern Ghats of Tamil Nadu, India (Gowande et al. 2020). The authors attempted to resolve the status of the previously ambiguously identified R. cf. leucolatus from this region (Ganesh Arumugam 2016) through an integrated approach using morphology, molecular DNA and call acoustics. Gowande et al. (2020) described the new species based on their morphology, biogeographic and acoustic data, for a shallow divergent lineage differing with 1.21.9% in the mitochondrial 16S gene from a closely related species R. charius. After a thorough reading of Gowande et al. (2020), we found serious flaws in the publication, as the authors overlooked many errors and misrepresented their own data, leaving their new taxon questionable with respect to its validity and status. In this work, despite pointing out these errors made by the authors, we also discuss the validity of their new taxon based on their results and suggest the way forward to resolving the issue. -.

Morphological and genetic variation in populations of Sitana/ marudhamneydhal/ and the validity of Sitana attenboroughii/.

Dewlap morphology and body ratios are two of the main morphological characters used in delimiting Sitana spp. It becomes a statistical limitation when small samples are used in species descriptions, as outliers can be picked to be described as a distinct species. Genetic data has been used to support the distinctness of a species in Sitana. However, species with shallow genetic divergence becomes a problem if not thoroughly examined. We examine and report our findings on morphological and genetic differences in two populations of Sitana marudhamneydhal and one population of S. attenboroughii. The shallow genetic divergence and overlapping morphology shows that Sitana attenboroughii is a junior synonym of Sitana marudhamneydhal.

Optimization of the Mechanical Properties and the Cytocompatibility for the PMMA Nanocomposites Reinforced with the Hydroxyapatite Nanofibers and the Magnesium Phosphate Nanosheets.

Commercial poly methyl methacrylate (PMMA)-based cement is currently used in the field of orthopedics. However, it suffers from lack of bioactivity, mechanical weakness, and monomer toxicity. In this study, a PMMA-based cement nanocomposite reinforced with hydroxyapatite (HA) nanofibers and two-dimensional (2D) magnesium phosphate MgP nanosheets was synthesized and optimized in terms of mechanical property and cytocompatibility. The HA nanofibers and the MgP nanosheets were synthesized using a hydrothermal homogeneous precipitation method and tuning the crystallization of the sodium-magnesium-phosphate ternary system, respectively. Compressive strength and MTT assay tests were conducted to evaluate the mechanical property and the cytocompatibility of the PMMA-HA-MgP nanocomposites prepared at different ratios of HA and MgP. To optimize the developed nanocomposites, the standard response surface methodology (RSM) design known as the central composite design (CCD) was employed. Two regression models generated by CCD were analyzed and compared with the experimental results, and good agreement was observed. Statistical analysis revealed the significance of both factors, namely, the HA nanofibers and the MgP nanosheets, in improving the compressive strength and cell viability of the PMMA-MgP-HA nanocomposite. Finally, it was demonstrated that the HA nanofibers of 7.5% wt and the MgP nanosheets of 6.12% wt result in the PMMA-HA-MgP nanocomposite with the optimum compressive strength and cell viability.

In Situ Visualization of Ferritin Biomineralization via Graphene Liquid Cell-Transmission Electron Microscopy.

Ferritin biomineralization is essential to regulate the toxic Fe2+ iron ions in the human body. Unravelling the mechanism of biomineralization in ferritin facilitates our understanding of the causes underlying many iron disorder-related diseases. Until now, no report of in situ visualization of ferritin biomineralization events at nanoscale exists due to the requirement for high-resolution imaging of nanometer-sized ferritin proteins in their hydrated states. Herein, for the first time, we show that the biomineralization processes within individual ferritin proteins can be visualized by means of graphene liquid cell-transmission electron microscopy (GLC-TEM). The increase in the ratio of Fe3+/Fe2+ ions over time monitored via electron energy loss spectroscopy (EELS) reveals the change in oxidation state of iron oxide phases with time. This study lays a foundation for future investigations on iron regulation mechanisms in healthy and dysfunctional ferritins.

A new Indian species of Rhinophis Hemprich, 1820 closely related to R. sanguineus Beddome, 1863 (Serpentes: Uropeltidae).

A new species of the uropeltid (shieldtail snake) genus Rhinophis is described based on a type series of seven specimens from the Wayanad region of the Western Ghats of peninsular India. The holotype was collected before 1880 but had been misidentified as the phenotypically similar and parapatric (possibly partly sympatric) R. sanguineus. Rhinophis karinthandani sp. nov. is diagnosed by a combination of 15 dorsal scale rows at midbody, 4-8 pairs of subcaudal scales, colour pattern (uniformly dark above, whitish below with extensive dark mottling), and by its distinct mitochondrial DNA sequences (e.g. 7.6% uncorrected p-distance for nd4). Phylogenetic analysis of mitochondrial DNA sequence data indicates that the new species is most closely related to R. sanguineus among currently recognised species, with this pair most closely related to the partly sympatric R. melanoleucus. The new species description brings the number of currently recognised species in the genus to 24, six of which are endemic to India and 18 endemic to Sri Lanka. A new key to the identification of Indian species of Rhinophis is provided.

A new species of Rhinophis Hemprich, 1820 (Serpentes: Uropeltidae) from the Wayanad region of peninsular India.

A new species of the shieldtail snake genus Rhinophis is described based on a type series of seven recently collected specimens from the Wayanad region of the Western Ghats of peninsular India. Rhinophis melanoleucus sp. nov. is diagnosed based on a combination of 15 dorsal scale rows at (or just behind) midbody, more than 215 ventral scales and a long rostral. The new species also has a distinctive (mostly black and white) colouration. A new key to the identification of Indian species of Rhinophis is provided.

Description of a new species of Xylophis Beddome, 1878 (Serpentes: Pareidae: Xylophiinae) from the Western Ghats, India.

We reassessed the systematics of the Indian (semi)fossorial snake Xylophis perroteti (Duméril, Bibron Duméril, 1854) based on morphological and DNA sequence data for type, historical, and new specimens. A population from the Anamalai Hills is distinct from broadly topotypic X. perroteti from the Nilgiri Hills (from which they are separated geographically by the lowland Palghat Gap) on the basis of both external morphology and DNA sequence data. We describe the Anamalai form as a new species, Xylophis mosaicus sp. nov. The new species is more closely related to X. perroteti than to X. stenorhynchus and X. captaini. A new key to identify the species of Xylophis is presented.

TEM Studies on Antibacterial Mechanisms of Black Phosphorous Nanosheets.

PURPOSE: Recently, two-dimensional (2D) nanomaterials are gaining tremendous attention as novel antibacterial platforms to combat against continuously evolving antimicrobial resistance levels. Among the family of 2D nanomaterials, black phosphorus (BP) nanosheets have demonstrated promising potential for biomedical applications. However, there is a need to gain nanoscale insights of the antibacterial activity of BP nanosheets which lies at the center of technical challenges. METHODS: Ultra-large BP nanosheets were synthesized by liquid-exfoliation method in the eco-friendly deoxygenated water. Synthesized BP nanosheets were characterized by TEM, AFM, and Raman spectroscopy techniques and their chemical stability was evaluated by EDS and EELS elemental analysis. The antibacterial activity of BP nanosheets was evaluated at nanoscale by the ultramicrotome TEM technique. Further, HAADF-STEM image and EDS elemental line map of the damaged bacterium were utilized to analyze the presence of diagnostic ions. Supportive SEM and ATR-FTIR studies were carried out to confirm the bacterial cell wall damage. In vitro colony counting method was utilized to evaluate the antibacterial performance of ultra-large BP nanosheets. RESULTS: Elemental EELS and EDS analysis of BP nanosheets stored in deoxygenated water confirmed the absence of oxygen peak. TEM studies indicate the various events of bacterial cell damage with the lost cellular metabolism and structural integrity. Colony counting test results show that as-synthesized BP nanosheets (100 µg/mL) can kill ~95% bacteria within 12 hours. CONCLUSION: TEM studies demonstrate the various events of E. coli membrane damage and the loss of structural integrity. These events include the BP nanosheets interaction with the bacterial cell wall, cytoplasmic leakage, detachment of cytoplasm from the cell membrane, reduced density of lipid bilayer and agglomerated DNA structure. The EDS elemental line mapping of the damaged bacterium confirms the disrupted cell membrane permeability and the lost cellular metabolism. SEM micrographs and ATR-FTIR supportive results confirm the bacterial cell wall damage.

Novel PMMA bone cement nanocomposites containing magnesium phosphate nanosheets and hydroxyapatite nanofibers.

Lack of bioactivity and monomer toxicity are limiting factors of polymethyl methacrylate (PMMA) bone cement in orthopedic applications. Herein, we address these shortcomings by proposing two-dimensional magnesium phosphate (MgP) nanosheets and hydroxyapatite (HA) nanofibers as novel fillers in PMMA bone cement nanocomposites. Two-dimensional MgP nanosheets and one-dimensional HA nanofibers were synthesized by tuning the crystallization of the sodium-magnesium-phosphate ternary system and hydrothermal homogeneous precipitation, respectively. We show that MgP nanosheets exhibit antibacterial properties against Escherichia coli (E. coli). In addition, HA nanofibers with high level of bioactivity are the proper choice to induce cell viability in the nanocomposite. Results indicate that the combination of both fillers can act as deformation locks enhancing the compressive strength of the nanocomposites. The synthesized nanocomposite possesses excellent bioactivity, mechanical properties, and cytocompatibility potentially opening new paradigm in the design of next generation bone cement composites.

On the structure and chemistry of iron oxide cores in human heart and human spleen ferritins using graphene liquid cell electron microscopy.

Ferritin is a protein that regulates the iron ions in humans by storing them in the form of iron oxides. Despite extensive efforts to understand the ferritin iron oxide structures, it is still not clear how ferritin proteins with a distinct light (L) and heavy (H) chain subunit ratio impact the biomineralization process. In situ graphene liquid cell-transmission electron microscopy (GLC-TEM) provides an indispensable platform to study the atomic structure of ferritin mineral cores in their native liquid environment. In this study, we report differences in the iron oxide formation in human spleen ferritins (HSFs) and human heart ferritins (HHFs) using in situ GLC-TEM. Scanning transmission electron microscopy (STEM) along with selected area electron diffraction (SAED) of the mineral core and electron energy loss spectroscopy (EELS) analyses enabled the visualization of morphologies, crystal structures and the chemistry of iron oxide cores in HSFs and HHFs. Our study revealed the presence of metastable ferrihydrite (5Fe2O3·9H2O) as a dominant phase in hydrated HSFs and HHFs, while a stable hematite (α-Fe2O3) phase predominated in non-hydrated HSFs and HHFs. In addition, a higher Fe3+/Fe2+ ratio was found in HHFs in comparison with HSFs. This study provides new understanding on iron-oxide phases that exist in hydrated ferritin proteins from different human organs. Such new insights are needed to map ferritin biomineralization pathways and possible correlations with various iron-related disorders in humans.

Capnocytophaga canimorsus sepsis with purpura fulminans and symmetrical gangrene following a dog bite in a shelter employee.

The authors describe a fatal case of purpura fulminans with symmetrical peripheral gangrene and sepsis caused by Capnocytophaga canimorsus in a 45-year-old, previously healthy woman who was bitten by a dog at an animal shelter where she was employed. Absent in this patient were the usual risk factors, including immunosuppression, alcohol abuse, corticosteroid therapy, and splenectomy. The patient's presentation to the emergency room late in the course of the infection probably effected her death. C canimorsus should be strongly suspected in any case of septicemia following a dog bite. Prompt therapy may influence the potentially fatal course of systemic infection. Employees and/or volunteers who work in animal shelters should be cognizant of the potential risks of a dog or cat bite and follow recommended procedures when such an incident occurs.