Non-indigenous Daphnia ‘pulex’ have been found in many lakes in New Zealand (NZ) in the past 20 years, suggesting a recent invasion. However, very little is known about the origin of invasive D. ‘pulex’, whether they are D. pulex or D. pulicaria, and whether they are obligately asexual clones or cyclical parthenogens. Furthermore, the source and time of arrival of the invasive genotype(s) are unclear. We address these questions by genomic sequencing Daphnia populations from 13 lakes on the South Island and one on the North Island, NZ. Based on ~24,000 monomorphic species-specific markers, the invasive Daphnia on the South Island were found to be D. pulicaria, while those on the North Island are D. pulex/ pulicaria hybrids. Both the South and North Island Daphnia are phylogenetically clustered with North American D. pulicaria/pulex, thereby suggesting their North American origins. We further found that the South Island Daphnia populations are fixed heterozygotes for nearly all bi-allelic sites in the nuclear genome and contain identical mitochondrial genomes, suggesting the origin and proliferation from a single founder clone, which we experimentally verified to be an obligate asexual. Estimates from molecular data imply a colonization time for the South Island populations of ~ 60 years ago, with a likely invasion route associated with the introduction of salmonids from North America. Key words： Daphnia pulex; Daphnia pulicaria; invasion; obligately asexual; hybridization
Hybridization between species is likely to be associated with a new ecological impact. However, in termites, reports of hybridization mostly focus on hybrid zones caused by species invasion or the development of initial-stage colonies. In this study, we combined microsatellite genotyping with mitochondrial DNA sequencing to investigate the hybridization and adaptive introgression between two sympatric, long-differentiated related termite species, Reticulitermes flaviceps and R. chinensis, in nature. Similar levels of mitochondrial and nuclear genetic diversity were found in R. flaviceps and R. chinensis. Asymmetric interspecific genetic differentiation was observed between mitochondrial and nuclear genes, with high genetic divergence found in mitochondrial DNA but low genetic divergence in nuclear genes. Our results indicated a lack of mitochondrial gene exchange in R. flaviceps and R. chinensis but unconstrained nuclear introgression between them. This asymmetric genetic differentiation between nuclear and cytoplasmic material strongly suggests that there is interspecific hybridization between R. flaviceps and R. chinensis in nature, which provides new insight into the dynamics of hybridization and its potential consequences for speciation in termites.
The goal of this research is to leverage computational molecular biophysics to guide process development, reduce experimental burden and focus purification activities on feasible targets. Here, we distill a complex separation problem (e.g. chromatographic retention of monoclonal antibodies) into a tangible model (ligand/protein complex), which is computationally feasible while preserving enough detail (atomistic level for interaction site) to support industrially relevant separation challenges. Computational docking, coupled with molecular dynamics simulation, produces results that are directionally consistent with chromatography for proteins (mAb). This approach is generalizable and can be applied to a range of ligands (AEX, CEX, and Mixed Mode). A detailed model of the chromatography base matrix (agarose) was constructed to obtain a biophysical understanding of potential protein/base matrix interactions. The base matrix was then modified in silico with ligands over a range of ligand densities representative of commercial chromatography resins to generate an agarose/ligand complex. A generic approach was developed to model the impact of avidity and ligand density on mAb/ligand interaction. The results revealed that increasing ligand density mask contributions of base matrix binding. Increasing the number of ligands that can interact with mAb results in more favorable free energy of binding or ΔG (more negative) with a limited incremental increase in ΔG by increasing N (number of ligands per agarose cluster) above three. Additionally, for protein/ligand interactions at each binding site, not all ligands contribute equally to the binding affinities or interaction energies and a redistribution of binding interactions/energies occur as N increases. These observations yield insights into the impact of avidity on retention (macroscopic affinity measurement via k’). The generic approach described in this manuscript can be leveraged to inform resin selection and design as well as targeted ligand selection/purification development in a rational manner.
Tiny predators, especially like phytoseiid mites, often experience a host of threats or stresses by fluctuating environmental factors. Heat acclimation as a superior adaptation strategy critically enhances abilities for organisms to handle with changing climate, but little is known about the molecular mechanism determining tolerant plastic responses in Phytoseiid mites. The relative expression of four identified HSP70 genes in two strains of Neoseiulus barkeri increased within a short time in temperature ramping treatment; meanwhile the expression of NbHSP70-1 and NbHSP70-2 in the conventional strain (CS) sharply decreased after 4 h displaying distinct contrast with the stable expression in the high-temperature adapted strain (HTAS). Western blot analysis showed that the protein level of NbHSP70-1 in CS was dramatically elevated at 0.5 h and decreased at 6 h at 42°C. Conversely, in HTAS, NbHSP70-1 was constantly induced and peaked at 6 h changed at 42°C. Furthermore, HSP70 suppression by RNAi knockdown had a greater influence on the survival of HTAS, causing a higher mortality under high temperature than CS. The recombinant certain exogenous NbHSP70-1 protein enhanced the viability of E. coli BL21 under lethal temperature of 50°C. These results suggested that HSP70 genes were a prominent contributor promoting the thermotolerance to heat stress and plastic change of HSP70 genes conferred the thermotolerance of HTAS through long-term heat acclimation. The divergent constitutive regulation of HSP70 to thermal is conducive to the flexible adaptability of predators in higher trophic level to trade off under extremely adversity stress.
The pattern of cyclic conjugation was thoroughly studied in the series of N- and P-acenaphthylene derivatives using several different aromaticity indices: the energy effect (ef), multicenter delocalization index (MCI), harmonic oscillator model of aromaticity (HOMA) index and nucleus independent chemical shifts (NICS). The Kekulé-structure-based reasoning predicts that there would be no cyclic conjugation in the “empty” five-membered heteroatom-containing rings in the studied molecules. It was found that, according to the ef, MCI and HOMA values, the extent of cyclic conjugation in the pentagonal rings is strongly influenced by the number and mutual arrangement of the hexagonal rings. In addition, it was revealed that in some of the examined molecules the intensity of cyclic conjugation in the “empty” pentagons is even stronger than that of some hexagonal rings within the same molecule. The obtained results refute what one would expect based on ”chemical intuition”, which is usually strongly rooted to the Kekulé structures.
Objectives: Second primary esophageal squamous cell neoplasms (ESCNs) are common in hypopharyngeal squamous cell carcinoma (HPSCC) patients and are associated with poor prognoses. The effectiveness of image-enhanced endoscopy (IEE) has not been well established. Design: Retrospective study with patients proven HPSCC between April 2016 and April 2018 receiving ESCNs screening via white-light imaging, narrow-band imaging, and Lugol chromoendoscopy. Setting: Data were collected from an electronic medical record at a single medical center in Taiwan. Participants: The study population included a total number of 130 patients with HPSCC receiving ESCNs screening via white-light imaging, narrow-band imaging, and Lugol chromoendoscopy Main Outcome Measures: Clinical data, incidence, and stage of second primary malignancy in HPSCC patients were obtained for statistical comparison. Results: Of 99 eligible patients, second primary ESCNs prevalence was 31%. Of the 69 patients assigned to the follow-up group, 23 with positive findings showed significantly increased previous histories of second primary malignancies in the upper aerodigestive tract. Among them, patients without symptoms at the time of IEE screening showed less advanced T stages and higher percentages of receiving minimally invasive therapy. Conclusions: Routine IEE screening is strongly recommended for HPSCC patients and can improve the detection rate of ESCNs and facilitate early-stage identification.
Glutarate is an attractive C5 platform chemical having wide application in nylon and plasticizer. However, microbial glutarate is mainly accumulated in the degradation of lysine and other methods were rarely explored for producing the glutarate from glucose directly. Here, we utilized a reversed adipic acid degradation pathway (RADP) and improved the glutarate production by increasing the precursors (malonyl-CoA and acetyl-CoA) based on the previously studied strain Bgl4146. Specifically, the conversion system of intracellular acetyl-CoA to malonyl-CoA was firstly constructed and optimized to balance acetyl-CoA synthase and acetyl-CoA carboxylase under different dissolved oxygen, enhancing the glutarate production from 0.09 g/L to 0.49 g/L. Then, modulating CoA balance by monitoring the expression of acetate kinase and pyruvate dehydrogenase resulting in a rise in glutarate titer up to 0.70 g/L. Finally, the optimized strain Bgl51464 was able to produce 7.97 g/L glutarate in a 5-L bioreactor. This strategy was described here, which could lay a certain foundation for the development of effective CoA balance to produce industrially high value-added chemicals.
COVID-19 outbreak has been a serious threat and it has been reported with different presentations and complications, here we report a 39 year old healthy male who presented with respiratory symptoms and investigation revealed that he is positive for SARS-CoV-2 and work up for Leukocytosis confirmed the diagnosis of CML.
Background Pediatric anticancer drug development has numerous challenges. Pediatric Research Equity Act (PREA) and the Best Pharmaceuticals for Children Act (BPCA), has been put forth to address the deficiency in pediatric drug development in general. Until recently, the requirement for pediatric evaluation of most oncology products for adult cancers was waived, because children typically do not have adult-type cancers or the indication or drug had been granted orphan designation. PREA therefore had no impact. Pediatric studies for labeling updates are largely done through BPCA by a Written Request (WR), issued by FDA. Because pediatric and adult populations do not share the same biology, natural history, or disease progression, there are limited opportunities to extrapolate adult information to pediatric. The requirements for the pediatric studies can vary greatly. Procedure In this study, we searched WRs that were issued by the FDA since 2001. We found 42 requests for pediatrics in oncology drugs and biologics. Results Studies included in 25 of the WRs have concluded, 18 have been given exclusivity, and 4 drugs have been approved for use in pediatric populations. The current status of the WRs are presented from regulatory, study design, dosing, formulation, analysis plan, evidential standard of efficacy and safety. Conclusions This would serve the purposes to study what has been requested over the years and what have been completed in response to the requirements. We consider this to be the anchor of pediatric cancer development for current stage and can potentially provide insight on how pediatric cancer drug development would change for the future years.
The performance of a series of density functionals has been tested for the insertions of ethylene, methyl acrylate (MA), and vinyl bromide (VB) catalyzed by α-diimine palladium complexes. Sixty-seven density functionals are screened, and the results are compared with available experimental data. Eleven hybrid functionals (M06, BHandH, mPW1PW91, HSEh1PBE, mPW3PBE, LC-ωPBE, mPW1PBE, PBE0, M06-HF, M06-2X, M05-2X) showed better performance in the insertions of both ethylene and MA, and could be therefore suitable for ethylene-MA copolymerization. Meanwhile, three GGA (PW91PW91, HCTH, HCTH407), two meta-GGA (TPSSTPSS, tHCTH), and ten hybrid functionals (M06, BHandH, TPSSh, B971, B98, B1B95, PBE0, M06-2X, tHCTHhyb, M05-2X) perform well in the ethylene-VB copolymerization. Besides, nine D3 or D3BJ augmented functionals are found to be suitable for both copolymerization systems. The D2 dispersion correction overestimated insertion energy barriers of these monomers and is unsuitable for such copolymerization. In addition, the double-zeta basis set is found to be sufficient for solvation single-point calculation of these systems.
The novel coronavirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has posed a serious threat to global public health. Respiratory failure followed by cardiovascular complications with wide-spread endothelial dysfunction and inflammation is rapidly emerging as a key threat in COVID-19. ACE-2 receptors are the cell-entry gate for SARS-CoV-2. Valproic Acid (VPA) is a proposed potential drug to treat COVID-19 but its mechanism of action is not well understood. We demonstrate that VPA-treatment significantly reduced ACE-2 expression in endothelial cells. VPA-treatment significantly reduced the expression of inflammatory cytokines IL-6 along with the endothelial activation marker ICAM-1. We provide evidence and discuss the plausible mechanism in detail for VPA use to prevent and treat COVID-19 in a personalized manner. Our study is expected to entice the scientific and clinical society to investigate VPA as a potential therapeutic option against COVID-19.
Osmium analogue to ruthenium anticancer drug NAMI-A; (ImH)[trans-OsCl4(DMSO)(Im)] (Im=imidazole, DMSO=dimethyl sulfoxide) (Os-NAMI-A) shows a three-fold higher activity in colon carcinoma. Hydrolysis mechanism of Os-NAMI-A has been investigated using density functional theory (DFT) in combination with CPCM solvation model. Calculated activation free energy values for the first chloro ligand hydrolysis in the gaseous and aqueous medium are found to be ΔGg=31.79 and ΔGaq=28.72 kcal/mol, respectively. While, activation free energy for the second cis chloro ligand hydrolysis calculated in the gas and solvent phases are observed to be significantly lower (ΔGg=29.12 and ΔGaq=22.61 kcal/mol), suggesting enhanced feasibility of second hydrolysis. However, hydrolysis of DMSO ligand in the formation of cis-[OsCl2(H2O)3(Im)]+ (P-3cis) is found to be thermodynamically preferred in aqueous medium (19.49 kcal/mol) with rate constant value of 3.20×10-2 s-1. In addition, molecular docking simulation reveals that cis-diaquated Os-NAMI-A (P-2cis) interacts with DNA (PDB ID: 1pgc) more effectively having binding energy -5.63 kcal/mol. Therefore, results of this investigation may lead us to understand the solution behaviour of osmium azole complexes as well as their mode of interaction with biomolecules which in return helps in potential anticancer drug designing.
Sexual dimorphism of plumage color is common in avians. A well-known example is mallard, in which drakes exhibit green head feathers, while females exhibit dull head feather color. Through microscopy observations, melanin was observed to be continuously deposited in feather barbules and to form a two-dimensional hexagonal lattice, which conferred the green feather coloration of drakes. Additionally, transcriptome analysis revealed that most pigmentation genes were highly expressed in feather follicles during the development of green feathers, which may contribute to melanin deposition. We identified 18 consensus differentially expressed genes in feather follicles by comparing the transcriptome differences in the male head vs. female head, male head vs. male back, and male head in the 7th week vs. male head in the 11th week. Among these genes, TYRP1 located on Z-chromosome of the mallard genome, showed an increasing trend in the feather follicles of drake heads during green feather development. In particular, its expression was 256 and 32 times higher in the head follicles of males than in those of the female head and the male back, respectively. Hence, the green feathers were determined by TYRP1 through sex-biased expression, which is common for genes linked with Z-chromosome in avians. The differential expression of TYRP1 in different body parts of males and among different time points may be due to differences in cis-regulation by transcription factors. We also demonstrated that the beautiful feather color of other male avians is largely caused by the sex-biased expression of pigmentation genes linked with Z-chromosome.
The growing epidemic of many age-related chronic diseases, such as cardiovascular diseases, diabetes, cancer, and neurodegenerative diseases, especially Parkinson's and Alzheimer's disease, places an increasing burden on the healthcare systems worldwide. In recent years, efforts to manipulate the consequences of aging have yielded some success, and naturally, identifying effective ways to slow down or even reverse aging has become increasingly popular. Importantly, existing drugs can be repurposed for anti-aging effects. Studies from model organisms and early stage human clinical trials have found that metformin and rapamycin, which respectively are an effective anti-diabetic medication and an immunosuppressant, have promising results in slowing aging and treating age-related diseases. These findings point to the possibility that these two anti-aging drug candidates, and especially their derivatives which may reduce side effects, are likely to become the first genuine rejuvenation medications to achieve healthy aging. Here, we present knowledge on the mechanisms that are involved in the anti-aging effect of the two molecules, followed by an outline of a host of potential aging-related clinical applications. We finally provide insights on the considerations and further directions for the development of anti-aging drugs.
i. Rationale, aims and objectives Antimicrobial Stewardship programs are critical for promoting and monitoring judicious use of antimicrobials, however, there are many well-established barriers to their effective implementation the rural setting. Pharmacist involvement in such programs is recommended as part of a multidisciplinary approach to improve appropriate antimicrobial prescribing. The aim of this study was to describe the impact of implementing a clinical pharmacy service on antimicrobial prescribing in a rural GP led hospital; explore areas of suboptimal antimicrobial prescribing; and review the change in total antimicrobial cost per patient day. ii. Methods: A retrospective case series audit of pre- and post-implementation of a new clinical pharmacy service was undertaken. All adult patients who had presented with sepsis, cellulitis, urinary tract infections and pneumonia between May and August 2015 and repeated for months in 2018 were included. Appropriateness of therapy was assessed using the National Antimicrobial Prescribing Survey guidelines. iii. Results: A total of 115 antibiotic orders from 2015 and 158 orders from 2018 were included. During admission, 86% of patients (55/64) in the post-intervention group were reviewed by a clinical pharmacist. Appropriate prescribing increased from 57% (66/115) in 2015 to 82% (129/158) in 2018 (P=0.001). Ceftriaxone was the most inappropriately prescribed antimicrobial. The cost of antimicrobial therapy was halved from $10.00 to $5.33 per patient day, pre- and post-implementation of a clinical pharmacy service respectively. iv. Conclusions: The implementation of a clinical pharmacy service in a small rural GP led hospital can significantly improve antimicrobial prescribing practices and provide considerable cost savings. Keywords Antimicrobial stewardship; antibiotics; pharmacists; hospitals, Rural; Inappropriate Prescribing