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1.
PLoS Biol ; 22(5): e3002617, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38696533

RESUMO

BAK and BAX execute intrinsic apoptosis by permeabilising the mitochondrial outer membrane. Their activity is regulated through interactions with pro-survival BCL-2 family proteins and with non-BCL-2 proteins including the mitochondrial channel protein VDAC2. VDAC2 is important for bringing both BAK and BAX to mitochondria where they execute their apoptotic function. Despite this important function in apoptosis, while interactions with pro-survival family members are well characterised and have culminated in the development of drugs that target these interfaces to induce cancer cell apoptosis, the interaction between BAK and VDAC2 remains largely undefined. Deep scanning mutagenesis coupled with cysteine linkage identified key residues in the interaction between BAK and VDAC2. Obstructive labelling of specific residues in the BH3 domain or hydrophobic groove of BAK disrupted this interaction. Conversely, mutating specific residues in a cytosol-exposed region of VDAC2 stabilised the interaction with BAK and inhibited BAK apoptotic activity. Thus, this VDAC2-BAK interaction site can potentially be targeted to either inhibit BAK-mediated apoptosis in scenarios where excessive apoptosis contributes to disease or to promote BAK-mediated apoptosis for cancer therapy.


Assuntos
Apoptose , Canal de Ânion 2 Dependente de Voltagem , Proteína Killer-Antagonista Homóloga a bcl-2 , Canal de Ânion 2 Dependente de Voltagem/metabolismo , Canal de Ânion 2 Dependente de Voltagem/genética , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Humanos , Ligação Proteica , Mitocôndrias/metabolismo , Animais , Células HEK293
2.
Hum Mol Genet ; 2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38879759

RESUMO

Venous thromboembolism (VTE) is a significant contributor to morbidity and mortality, with large disparities in incidence rates between Black and White Americans. Polygenic risk scores (PRSs) limited to variants discovered in genome-wide association studies in European-ancestry samples can identify European-ancestry individuals at high risk of VTE. However, there is limited evidence on whether high-dimensional PRS constructed using more sophisticated methods and more diverse training data can enhance the predictive ability and their utility across diverse populations. We developed PRSs for VTE using summary statistics from the International Network against Venous Thrombosis (INVENT) consortium genome-wide association studies meta-analyses of European- (71 771 cases and 1 059 740 controls) and African-ancestry samples (7482 cases and 129 975 controls). We used LDpred2 and PRS-CSx to construct ancestry-specific and multi-ancestry PRSs and evaluated their performance in an independent European- (6781 cases and 103 016 controls) and African-ancestry sample (1385 cases and 12 569 controls). Multi-ancestry PRSs with weights tuned in European-ancestry samples slightly outperformed ancestry-specific PRSs in European-ancestry test samples (e.g. the area under the receiver operating curve [AUC] was 0.609 for PRS-CSx_combinedEUR and 0.608 for PRS-CSxEUR [P = 0.00029]). Multi-ancestry PRSs with weights tuned in African-ancestry samples also outperformed ancestry-specific PRSs in African-ancestry test samples (PRS-CSxAFR: AUC = 0.58, PRS-CSx_combined AFR: AUC = 0.59), although this difference was not statistically significant (P = 0.34). The highest fifth percentile of the best-performing PRS was associated with 1.9-fold and 1.68-fold increased risk for VTE among European- and African-ancestry subjects, respectively, relative to those in the middle stratum. These findings suggest that the multi-ancestry PRS might be used to improve performance across diverse populations to identify individuals at highest risk for VTE.

3.
Antimicrob Agents Chemother ; 68(3): e0139923, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38329330

RESUMO

Non-clinical antibiotic development relies on in vitro susceptibility and infection model studies. Validating the achievement of the targeted drug concentrations is essential to avoid under-estimation of drug effects and over-estimation of resistance emergence. While certain ß-lactams (e.g., imipenem) and ß-lactamase inhibitors (BLIs; clavulanic acid) are believed to be relatively unstable, limited tangible data on their stability in commonly used in vitro media are known. We aimed to determine the thermal stability of 10 ß-lactams and 3 BLIs via LC-MS/MS in cation-adjusted Mueller Hinton broth at 25 and 36°C as well as agar at 4 and 37°C, and in water at -20, 4, and 25°C. Supplement dosing algorithms were developed to achieve broth concentrations close to their target over 24 h. During incubation in broth (pH 7.25)/agar, degradation half-lives were 16.9/21.8 h for imipenem, 20.7/31.6 h for biapenem, 29.0 h for clavulanic acid (studied in broth only), 23.1/71.6 h for cefsulodin, 40.6/57.9 h for doripenem, 46.5/64.6 h for meropenem, 50.8/97.7 h for cefepime, 61.5/99.5 h for piperacillin, and >120 h for all other compounds. Broth stability decreased at higher pH. All drugs were ≥90% stable for 72 h in agar at 4°C. Degradation half-lives in water at 25°C were >200 h for all drugs except imipenem (14.7 h, at 1,000 mg/L) and doripenem (59.5 h). One imipenem supplement dose allowed concentrations to stay within ±31% of their target concentration. This study provides comprehensive stability data on ß-lactams and BLIs in relevant in vitro media using LC-MS/MS. Future studies are warranted applying these data to antimicrobial susceptibility testing and assessing the impact of ß-lactamase-related degradation.


Assuntos
Inibidores de beta-Lactamases , beta-Lactamas , Inibidores de beta-Lactamases/farmacologia , beta-Lactamas/farmacologia , Doripenem , Ágar , Cromatografia Líquida , Espectrometria de Massas em Tandem , Antibacterianos/farmacologia , Penicilinas , Ácido Clavulânico/farmacologia , Imipenem/farmacologia , Água , Testes de Sensibilidade Microbiana
4.
Anal Chem ; 96(18): 7047-7055, 2024 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-38653469

RESUMO

Raman spectroscopy can provide nonbiased single-cell analysis based on the endogenous ensemble of biomolecules, with alterations in cellular content indicative of cell state and disease. The measurements themselves can be performed in a variety of modes: generally, full imaging takes the most time but can provide the most information. By reducing the imaging resolution and generating the most characteristic single-cell Raman spectrum in the shortest time, we optimize the utility of the Raman measurement for cell phenotyping. Here, we establish methods to compare these different measurement approaches and assess what, if any, undesired effects occur in the cell. Assuming that laser-induced damage should be apparent as a change in molecular spectra across sequential measurements, and by defining the information content as the Raman-based separability of two cell lines, we thereby establish a parameter range for optimum measurement sensitivity and single-cell throughput in single-cell Raman spectroscopic analysis. While the work here uses 532 nm irradiation, the same approach can be generalized to Raman analysis at other wavelengths.


Assuntos
Análise de Célula Única , Análise Espectral Raman , Análise Espectral Raman/métodos , Análise de Célula Única/métodos , Humanos , Fenótipo , Ensaios de Triagem em Larga Escala
5.
Gastrointest Endosc ; 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39147104

RESUMO

BACKGROUND AND AIMS: There is growing evidence for the role of cold piecemeal endoscopic mucosal resection (C-EMR) in the treatment of colorectal lesions ≥10mm. However, it is unclear if it is equally efficacious for all histologic subtypes and sizes. This retrospective study compares the efficacy and safety of C-EMR in the resection of medium (10-19mm) and large (≥20mm) serrated and adenomatous lesions. METHODS: A retrospective analysis was performed of Paris IIa colonic lesions resected utilising a C-EMR technique over a 3.5 year period at our center. RESULTS: C-EMR was performed for 242 lesions in 151 patients. Lesion size ranged between 10mm to 50mm, with median size of 20mm. Ninety-five polyps were adenomatous, with 147 sessile serrated lesions (SSLs). At six month surveillance colonoscopy, the combined recurrence rate was 6.2%. Adenomas ≥20mm demonstrated a higher rate of recurrence (16.1%) compared to large SSLs (4.1%), medium adenomas (3.0%), and medium SSLs (1.4%). There were no adverse events reported following C-EMR. CONCLUSIONS: C-EMR seems to be less effective for the resection of large adenomas when compared to medium adenomas or large SSLs. C-EMR is equally safe for all lesion size and histology.

6.
Langmuir ; 40(3): 1658-1665, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38179938

RESUMO

The surface resistivity of boroaluminosilicate display glasses, which may affect the downstream display panel manufacturing, varies with the relative humidity (RH) of the environment, but the origin of this RH dependence has not been well understood. We have measured the water adsorption behavior on Corning Eagle XG (Glass-E) and Lotus NXT (Glass-L) glass panels using Brewster angle transmission infrared spectroscopy. The IR spectra of adsorbed water were analyzed to obtain the effective thickness of adsorbed water, the distribution of hydrogen-bonding interactions among the adsorbed water molecules, and the isosteric heat of water adsorption. These characteristics were compared with the electrical conductivity (inverse of resistivity) of these two glasses [Appl. Surf. Sci. 2015, 356, 1189]. This comparison revealed the correlation between the conductivity and the water layer structure, which could explain the surface resistivity difference between Glass-E and Glass-L as a function of RH. This study also disputed the previous hypothesis that the water adsorption isotherm would be governed by the areal density of the surface hydroxyl group; instead, it suggested that the network modifier ions may also play a critical role, especially in the intermediate RH regime.

8.
Mil Psychol ; 32(6): 441-449, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-38536334

RESUMO

Prior research has demonstrated the impact of military sexual trauma (MST) on health and well-being. However, little empirical work has been published identifying protective factors for women who have experienced MST. We examined the impact of two different forms of MST, harassment-only and assault MST, on PTSD symptoms and social functional impairment in a sample of women Veterans employed in the civilian workforce. The effects of MST were examined at three different times over a period of 9 months. We found that MST that included both harassment and assault was associated with significantly higher levels of PTSD symptoms and social functional impairment across three different time points among women Veterans employed in civilian jobs. Further, the pattern of results suggested that coworker support can buffer against these negative outcomes experienced by women who reported assault MST. Overall, findings suggest that coworker support is one critical resource for women Veterans who experienced assault MST.

10.
J Wrist Surg ; 13(1): 66-74, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38264128

RESUMO

Background The results of Mathoulin's arthroscopic dorsal capsuloligamentous reconstruction (ADCLR) are excellent in many patients with scapholunate instability, though less consistently good in higher grade instabilities. The purpose of this article is to describe a novel technique of volar scaphotrapeziotrapezoid (STT) reconstruction which may be used to augment rotational control of the scaphoid, in conjunction with the ADCLR, for use in European Wrist Arthroscopy Society (EWAS) grade IV/V instabilities. Description of Technique Following completion of ADCLR, the STT joint is approached through the flexor carpi radialis sheath. The palmaris longus tendon is harvested. Fluoroscopy is used to site guide wires for tunnel placement in the distal scaphoid and the proximal trapezium; 3.5-mm tunnels are overdrilled in both bones, to a depth of 8 mm. The palmaris graft is then anchored in the scaphoid tunnel with a mini-DX SwiveLock anchor. The graft is tensioned, then anchored in the trapezium tunnel with another anchor. Patients and Methods We retrospectively selected two young men heavy manual workers who had this procedure more than 12 months previously for scapholunate instability, with static radiographic abnormalities and a drive through sign (EWAS grade V). The patients were reviewed after 12 months, for assessment of visual analog scale, quick disabilities of the arm, shoulder, and hand, and patient-rated wrist/hand evaluation scores, range of motion, and grip strength. Results Both patients had marked improvements of wrist comfort and function at 1 year, and were able to return to their normal duties at work and complete all activities of daily living with minimal symptoms. Conclusion This volar STT reconstruction may expand the success of the Mathoulin's ADCLR into higher grade instabilities.

11.
PLoS One ; 19(3): e0297893, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38446769

RESUMO

BACKGROUND: The queen bee phenomenon (QBP) describes the behavioural response that occurs when women achieve success in a male-dominated environment, and in this position of authority, treat their female subordinates more critically. It has been demonstrated in business, academia, the military, and police force. The goal of this study was to determine whether the QBP occurs in surgical specialties. We hypothesized that female surgeons, fellows, and senior surgical residents would be more critical in their assessment of junior female residents than their male counterparts. METHODS: A scenario-based survey was distributed via email to all Canadian surgical programs between February and March 2021. Scenarios were designed to assess either female or male learners. Centers distributed surveys to attending surgeons, surgical fellows, resident physicians, and affiliate surgeons. Respondents average Likert score for female-based and male-based questions were calculated. Subgroup analyses were performed based on gender, age, seniority, and surgical specialty. RESULTS: 716 survey responses were collected, with 387 respondents identifying as male (54%) and 321 identifying as female (45%). 385 attending surgeons (54%), 66 fellows (9%), and 263 residents (37%) responded. The mean Likert scores for female respondents assessing female learners was significantly lower than male learners (p = 0·008, CI = 95%). During subgroup analysis, some specialties demonstrated significant scoring differences. DISCUSSION: The QBP was shown to be present among surgical specialties. Female respondents assessed female learners more critically than their male counterparts. CONCLUSION: These findings highlight the importance of tackling organizational biases to create more equitable educational and work environment in surgery.


Assuntos
Meio Ambiente , Especialidades Cirúrgicas , Feminino , Abelhas , Masculino , Humanos , Animais , Canadá , Escolaridade , Comércio
12.
Front Pharmacol ; 15: 1339858, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38895629

RESUMO

Objectives: We sought to evaluate the pharmacodynamics of ß-lactam antibacterials against polymicrobial communities of clinically relevant gram-positive and gram-negative pathogens. Methods: Two Enterococcus faecalis isolates, two Staphylococcus aureus isolates, and three Escherichia coli isolates with varying ß-lactamase production were evaluated in static time-killing experiments. Each gram-positive isolate was exposed to a concentration array of ampicillin (E. faecalis) or cefazolin (S. aureus) alone and during co-culture with an E. coli isolate that was ß-lactamase-deficient, produced TEM-1, or produced KPC-3/TEM-1B. The results of the time-killing experiments were summarized using an integrated pharmacokinetic/pharmacodynamics analysis as well as mathematical modelling to fully characterize the antibacterial pharmacodynamics. Results: In the integrated analysis, the maximum killing of ampicillin (Emax) against both E. faecalis isolates was ≥ 4.11 during monoculture experiments or co-culture with ß-lactamase-deficient E. coli, whereas the Emax was reduced to ≤ 1.54 during co-culture with ß-lactamase-producing E. coli. In comparison to monoculture experiments, culturing S. aureus with KPC-producing E. coli resulted in reductions of the cefazolin Emax from 3.25 and 3.71 down to 2.02 and 2.98, respectively. Two mathematical models were created to describe the interactions between E. coli and either E. faecalis or S. aureus. When in co-culture with E. coli, S. aureus experienced a reduction in its cefazolin Kmax by 24.8% (23.1%RSE). Similarly, ß-lactamase-producing E. coli preferentially protected the ampicillin-resistant E. faecalis subpopulation, reducing Kmax,r by 90.1% (14%RSE). Discussion: ß-lactamase-producing E. coli were capable of protecting S. aureus and E. faecalis from exposure to ß-lactam antibacterials.

13.
Injury ; 55(6): 111546, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38599010

RESUMO

INTRODUCTION: Currently there is no consensus on the need for investigating knee ligamentous and meniscal injuries in a patient with a tibial plateau fracture. Consequently, many soft tissue injuries are likely undiagnosed and therefore untreated. The impact this has on long term knee outcomes is not well defined. We aimed to identify the impacts of various diagnostic methods on the management of meniscal injuries associated with tibial plateau fractures and evaluate the clinical outcomes. MATERIALS AND METHODS: We performed a systematic review using Pubmed, Medline, Embase, CINAHL and Cochrane following Cochrane guidelines. We included studies that operatively managed tibial plateau fractures and soft tissue injuries, which were diagnosed with either preoperative MRI, intra-operative arthroscopy or arthrotomy. RESULTS: 18 articles with 884 people, with a mean age of 46.4 years were included. Soft tissue injuries were detected on MRI (32-73%) and arthroscopy (12-70%), of which the most common were lateral meniscal injuries (7-64% of tibial plateau fractures). When identified by arthroscopy and arthrotomy, these injuries were almost always treated, either by repair or debridement. The clinical outcomes of these patients were poorly reported, with a heterogenous use of patient reported outcome measures, and follow up time points. There were no randomised trials or control groups for comparative analysis, however operative treatment yielded good to excellent outcomes. CONCLUSION: There is a high incidence of concomitant soft tissue injuries with tibial plateau fractures, particularly lateral meniscal injuries. There are 2 main approaches to meniscal injuries: surgeons who don't investigate, don't treat, whilst surgeons who do investigate often do surgically treat. Although studies that treated these injuries achieved good to excellent results, the currently available evidence doesn't confirm treatment superiority. As there is plausibility for better outcomes, randomised studies are needed to further investigate this clinical question.


Assuntos
Artroscopia , Imageamento por Ressonância Magnética , Lesões dos Tecidos Moles , Lesões do Menisco Tibial , Fraturas do Planalto Tibial , Humanos , Artroscopia/métodos , Desbridamento/métodos , Traumatismos do Joelho/cirurgia , Traumatismos do Joelho/diagnóstico por imagem , Lesões dos Tecidos Moles/cirurgia , Lesões dos Tecidos Moles/diagnóstico por imagem , Lesões do Menisco Tibial/cirurgia , Lesões do Menisco Tibial/diagnóstico por imagem , Fraturas do Planalto Tibial/diagnóstico por imagem , Fraturas do Planalto Tibial/cirurgia
14.
Knee ; 49: 226-240, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39043018

RESUMO

BACKGROUND: Anterior cruciate ligament reconstruction (ACLR) is most commonly performed with hamstring tendon (HT) or bone-patellar tendon-bone (BTB) autografts, although the quadriceps tendon (QT) autograft has recently increased in popularity. This systematic review and meta-analysis review compares QT and HT autografts for primary ACLR with a sole focus on randomised controlled trials (RCTs). METHODS: A prospective protocol was registered on PROSPERO (CRD42023427339). The search included MEDLINE, Embase and Web of Science until February 2024. Only comparative RCTs were included. The primary outcome was the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form score. Secondary outcomes included: other validated patient-reported outcome measures (PROMs), objective strength scores, complications, and return to sport and work. RESULTS: From 2,609 articles identified, seven were included (n = 474 patients). This meta-analysis did not identify a significant difference in post-operative IKDC scores (5 articles; p = 0.73), Lysholm scores (3 studies; p = 0.80) or Tegner activity scales (2 studies; p = 0.98). There were no differences in graft failure rates (4 studies; p = 0.92) or in overall adverse events (4 studies; p = 0.83) at 24 months post-ACLR as per meta-analysis. Donor site morbidity scores were significantly lower in the QT group (MD -4.67, 95% CI -9.29 to -0.05; 2 studies, 211 patients; p = 0.05, I2 = 34%). CONCLUSION: There were no differences between QT and HT in PROMs, graft failure rates or overall complications based on low- to moderate-quality evidence. There may possibly be lower donor site morbidity with the QT autograft, however, the evidence is not sufficient to draw definitive conclusions.


Assuntos
Reconstrução do Ligamento Cruzado Anterior , Tendões dos Músculos Isquiotibiais , Ensaios Clínicos Controlados Aleatórios como Assunto , Humanos , Reconstrução do Ligamento Cruzado Anterior/métodos , Tendões dos Músculos Isquiotibiais/transplante , Lesões do Ligamento Cruzado Anterior/cirurgia , Músculo Quadríceps/transplante , Tendões/transplante , Autoenxertos , Transplante Autólogo
15.
Nat Commun ; 15(1): 151, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167372

RESUMO

Unlike for DNA and RNA, accurate and high-throughput sequencing methods for proteins are lacking, hindering the utility of proteomics in applications where the sequences are unknown including variant calling, neoepitope identification, and metaproteomics. We introduce Spectralis, a de novo peptide sequencing method for tandem mass spectrometry. Spectralis leverages several innovations including a convolutional neural network layer connecting peaks in spectra spaced by amino acid masses, proposing fragment ion series classification as a pivotal task for de novo peptide sequencing, and a peptide-spectrum confidence score. On spectra for which database search provided a ground truth, Spectralis surpassed 40% sensitivity at 90% precision, nearly doubling state-of-the-art sensitivity. Application to unidentified spectra confirmed its superiority and showcased its applicability to variant calling. Altogether, these algorithmic innovations and the substantial sensitivity increase in the high-precision range constitute an important step toward broadly applicable peptide sequencing.


Assuntos
Aprendizado Profundo , Algoritmos , Análise de Sequência de Proteína/métodos , Peptídeos/química , Sequência de Aminoácidos
16.
ANZ J Surg ; 94(4): 614-620, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38240147

RESUMO

BACKGROUND: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is the standard of care for selected cases of peritoneal surface malignancy. However, due to its morbidity and learning curve, it is only delivered in six centres in Australia and Aotearoa New Zealand (AoNZ). In this study, we report peri-operative morbidity and mortality following CRS/HIPEC at Waikato and Braemar Hospitals, which have treated patients from all regions of AoNZ since 2008. METHODS: We retrospectively reviewed a database of all patients undergoing CRS and HIPEC from 01/01/2008 to 01/11/2020 at Waikato and Braemar Hospitals. RESULTS: Two-hundred and forty procedures were performed for 221 patients with a mean age of 55, including 22 (9.2%) re-do procedures. One hundred and eighty-six cases were European, 32 were Maori, and 16 were Pasifika. There were 152 pseudomyxoma peritonei, 39 colorectal adenocarcinomas, 29 appendiceal cancers, 8 ovarian cancers, 6 peritoneal mesothelioma, and 6 other tumour types. The median PCI was 16. HIPEC was administered to 196 out of 196 CC0/1 cases (100%) and 3 out of 44 CC2/3 cases (6.8%). Fifty-six cases (23.3%) had at least one major complication. There were two mortalities (0.8%) within 30 days. The median length of stay was 11 days. Operative duration was identified as an independent risk factor for major complications. There was considerable variation in the number of referrals from different regions of AoNZ. Over time, a decline in major complication rate is seen with increased case volume. CONCLUSION: The Waikato region has achieved favourable short-term outcomes following CRS/HIPEC.


Assuntos
Procedimentos Cirúrgicos de Citorredução , Quimioterapia Intraperitoneal Hipertérmica , Neoplasias Peritoneais , Feminino , Humanos , Pessoa de Meia-Idade , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Terapia Combinada , Procedimentos Cirúrgicos de Citorredução/métodos , Nova Zelândia/epidemiologia , Neoplasias Peritoneais/patologia , Estudos Retrospectivos , Taxa de Sobrevida
17.
Nanoscale ; 16(10): 5242-5256, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38362911

RESUMO

The structure and catalytic properties of Cu nanoclusters of sizes between 55 and 147 atoms were examined to understand if small Cu clusters could provide enhancement over traditional catalysts for the electrocatalysis of CO2 to CO and carbon-based fuels, such as CH4 and CH3OH, compared to bulk Cu surfaces and large Cu nanoparticles. Clusters studied included Cu55, Cu78, Cu101, Cu124, and Cu147, the structures of which were determined using global optimisation. The majority of Cu clusters examined were icosahedral, including the perfect closed-shell, partial-shell, elongated and distorted icosahedral clusters. Free energy diagrams for the reduction of CO2 showed the potential required for the formation of CO is notably smaller for all cluster sizes considered, relative to Cu(111). Less variation is observed for the limiting potential for the formation of CH4 and CH3OH. However, it was found that clusters that are either a distorted motif or contain vacancy defects yielded the best activity and provide an interesting synthesis target for future experiments.

18.
Nat Commun ; 15(1): 1219, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336770

RESUMO

Plants with the C4 photosynthesis pathway typically respond to climate change differently from more common C3-type plants, due to their distinct anatomical and biochemical characteristics. These different responses are expected to drive changes in global C4 and C3 vegetation distributions. However, current C4 vegetation distribution models may not predict this response as they do not capture multiple interacting factors and often lack observational constraints. Here, we used global observations of plant photosynthetic pathways, satellite remote sensing, and photosynthetic optimality theory to produce an observation-constrained global map of C4 vegetation. We find that global C4 vegetation coverage decreased from 17.7% to 17.1% of the land surface during 2001 to 2019. This was the net result of a reduction in C4 natural grass cover due to elevated CO2 favoring C3-type photosynthesis, and an increase in C4 crop cover, mainly from corn (maize) expansion. Using an emergent constraint approach, we estimated that C4 vegetation contributed 19.5% of global photosynthetic carbon assimilation, a value within the range of previous estimates (18-23%) but higher than the ensemble mean of dynamic global vegetation models (14 ± 13%; mean ± one standard deviation). Our study sheds insight on the critical and underappreciated role of C4 plants in the contemporary global carbon cycle.


Assuntos
Dióxido de Carbono , Fotossíntese , Dióxido de Carbono/metabolismo , Fotossíntese/fisiologia , Poaceae/metabolismo , Plantas/metabolismo , Zea mays/metabolismo
19.
Int J Antimicrob Agents ; 64(3): 107260, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38945177

RESUMO

OBJECTIVES: The proliferation of metallo-ß-lactamase (MBL)-producing Pseudomonas aeruginosa represents a significant public health threat. P. aeruginosa undergoes significant phenotypic changes that drastically impair antibiotic efficacy. The objectives of this study were (1) to quantify the time-course of killing of VIM-2-producing P. aeruginosa in response to aztreonam-based therapies (including avibactam for coverage of AmpC), and (2) to document the capacity of P. aeruginosa to undergo morphological transformations that facilitate persistence. METHODS: A well-characterised, clinical VIM-2-producing P. aeruginosa was studied in the hollow fibre infection model (HFIM) over 9 days (7 days of active antibiotic therapy, 2 days of treatment withdrawal) at a 107.5 CFU/mL starting inoculum. HFIM treatment arms included: growth control, aztreonam, ceftazidime/avibactam, aztreonam/ceftazidime/avibactam, polymyxin B, and aztreonam/ceftazidime/avibactam/polymyxin B. In addition, real-time imaging studies were conducted under static conditions to determine the time course of the reversion of persister cells. RESULTS: There was a pronounced discrepancy between OD620 and bacterial counts obtained from plating methods (hereafter referred to as 'OD-count discrepancy'). For aztreonam monotherapy, observed counts were 0 CFU/mL by 120 h. Despite this, there was a significant OD-count discrepancy compared with the pre-treatment 0 h. Between therapy withdrawal at 168 h and 216 h, all arms with suppressed counts had regrown to the system-carrying capacity. Real-time imaging of the P. aeruginosa filaments after drug removal showed rapid reversion from a long, filamentous phenotype to many individual rods within 2 h. CONCLUSION: Managing MBL-producing P. aeruginosa requires a multifaceted approach, focused on maximising killing and minimising proliferation of resistant and persistent subpopulations, which will involve eliminating drug-induced phenotypic transformers.

20.
NAR Genom Bioinform ; 6(2): lqae031, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38666213

RESUMO

DNA variation analysis has become indispensable in many aspects of modern biomedicine, most prominently in the comparison of normal and tumor samples. Thousands of samples are collected in local sequencing efforts and public databases requiring highly scalable, portable, and automated workflows for streamlined processing. Here, we present nf-core/sarek 3, a well-established, comprehensive variant calling and annotation pipeline for germline and somatic samples. It is suitable for any genome with a known reference. We present a full rewrite of the original pipeline showing a significant reduction of storage requirements by using the CRAM format and runtime by increasing intra-sample parallelization. Both are leading to a 70% cost reduction in commercial clouds enabling users to do large-scale and cross-platform data analysis while keeping costs and CO2 emissions low. The code is available at https://nf-co.re/sarek.

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