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1.
Lancet HIV ; 2024 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-39489933

RESUMEN

The sex of people living with HIV-1 infection, schistosome infection, or both, is a fundamental determinant of their clinical outcomes and of how these two infections interact in the host. Data from longitudinal and cross-sectional human studies and animal models indicate that males with HIV-1 and schistosome co-infection excrete fewer schistosome eggs and might have higher HIV-1 RNA viral loads and greater liver damage. Females with schistosome infection appear to have higher risk of HIV-1 acquisition than females without, particularly in Schistosoma haematobium infection, and a greater risk of death in HIV-1 and schistosome co-infection. Greater transmission of HIV-1 to partners has been shown in both sexes in those with schistosome infection. Biological sex is a consequential factor affecting pathophysiological and clinical responses in HIV-1 and schistosome co-infection. Designing future analyses to incorporate sex is vital to optimise research and care for people living with HIV-1, schistosomes, and HIV-1 and schistosome co-infection.

2.
Bioinform Biol Insights ; 18: 11779322241285982, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39410943

RESUMEN

Deubiquitinating enzymes (DUBs) prevent ubiquitination by eliminating ubiquitin from their substrates. Deubiquitinating enzymes have important roles in a number of cell biology subfields that are highly relevant to diseases like neurodegeneration, cancer, autoimmune disorders, and long-term inflammation. Deubiquitinating enzymes feature a well-defined active site and, for the most part, catalytic cysteine, which makes them appealing targets for small-molecule drug development. Ubiquitin-specific protease 46 (USP46) is a member of the ubiquitin-specific protease family, the largest subfamily of DUBs. Over the past 10 years, some studies have steadily demonstrated the significance of USP46 in several biological processes, although it was identified later and early research progress was modest. Specifically, in the last few years, the carcinogenic properties of USP46 have become more apparent. In the current review, we provide a comprehensive overview of the current knowledge about USP46 including its characteristics, structure, inhibitors, function in diseases, especially in the nervous system, and the correlation of USP46 with cancers.

4.
Endosc Int Open ; 12(10): E1143-E1149, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39398449

RESUMEN

Background and study aims Although outcomes of lumen-apposing metal stents (LAMS) placement in native anatomy have been reported, data on LAMS placement in surgically altered anatomy (SAA) are sparse. We aimed to assess outcomes of LAMS placement in patients with SAA for different indications. Patients and methods This was an international, multicenter, retrospective, observational study at 25 tertiary care centers through November 2023. Consecutive patients with SAA who underwent LAMS placement were included. The primary outcome was technical success defined as correct placement of LAMS. Secondary outcomes were clinical success and safety. Results Two hundred and seventy patients (125 males; average age 61 ± 15 years) underwent LAMS placement with SAA. Procedures included EUS-directed transgastric ERCP (EDGE) and EUS-directed transenteric ERCP (EDEE) (n = 82), EUS-guided entero-enterostomy (n = 81), EUS-guided biliary drainage (n = 57), EUS-guided drainage of peri-pancreatic fluid collections (n = 48), and EUS-guided pancreaticogastrostomy (n = 2). Most cases utilized AXIOS stents (n = 255) compared with SPAXUS stents (n = 15). Overall, technical success was 98%, clinical success was 97%, and the adverse event (AE) rate was 12%. Using AGREE classification, five events were rated as Grade II, 21 events as Grade IIIa, and six events as IIIb. No difference in AEs were noted among stent types ( P = 0.52). Conclusions This study shows that placement of LAMS is associated with high technical and clinical success rates in patients with SAA. However, the rate of AEs is noteworthy, and thus, these procedures should be performed by expert endoscopists at tertiary centers.

5.
bioRxiv ; 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39345636

RESUMEN

Cardiovascular diseases (CVDs) and pathologies are often driven by changes in molecular signaling and communication, as well as in cellular and tissue components, particularly those involving the extracellular matrix (ECM), cytoskeleton, and immune response. The fine-wire vascular injury model is commonly used to study neointimal hyperplasia and vessel stiffening, but it is not typically considered a model for CVDs. In this paper, we hypothesize that vascular injury induces changes in gene expression, molecular communication, and biological processes similar to those observed in CVDs at both the transcriptome and protein levels. To investigate this, we analyzed gene expression in microarray datasets from injured and uninjured femoral arteries in mice two weeks post-injury, identifying 1,467 significantly and differentially expressed genes involved in several CVDs such as including vaso-occlusion, arrhythmia, and atherosclerosis. We further constructed a protein-protein interaction network with seven functionally distinct clusters, with notable enrichment in ECM, metabolic processes, actin-based process, and immune response. Significant molecular communications were observed between the clusters, most prominently among those involved in ECM and cytoskeleton organizations, inflammation, and cell cycle. Machine Learning Disease pathway analysis revealed that vascular injury-induced crosstalk between ECM remodeling and immune response clusters contributed to aortic aneurysm, neovascularization of choroid, and kidney failure. Additionally, we found that interactions between ECM and actin cytoskeletal reorganization clusters were linked to cardiac damage, carotid artery occlusion, and cardiac lesions. Overall, through multi-scale bioinformatic analyses, we demonstrated the robustness of the vascular injury model in eliciting transcriptomic and molecular network changes associated with CVDs, highlighting its potential for use in cardiovascular research.

6.
Endosc Int Open ; 12(9): E1065-E1074, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39285860

RESUMEN

The first Asia-Pacific consensus recommendations for endoscopic and interventional management of hilar cholangiocarcinoma were published in 2013. Since then, new evidence on the role of endoscopy for management of malignant hilar biliary obstruction (MHBO) has emerged. To update the recommendation, we reviewed the literature using a PICO (population/intervention/comparison/outcomes) framework and created consensus statements. The expert panel voted anonymously using the modified Delphi method and all final statements were evaluated for the quality of evidence and strength of recommendation. The important points with inadequate supporting evidence were classified as key concepts. There were seven statements and five key concepts that reached consensus. The statements and key concepts dealt with multiple aspects of endoscopy-based management in MHBO starting from diagnosis, strategies and options for biliary drainage, management of recurrent biliary obstruction, management of cholecystitis after biliary stenting, and adjunctive treatment before stenting. Although the recommendations may assist physicians in planning the treatment for MHBO patients, they should not replace the decision of a multidisciplinary team in the management of individual patients.

7.
One Health ; 19: 100857, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39077329

RESUMEN

Vietnam's unprecedented demand for meat from livestock, including pigs and farmed wildlife, underscores the importance of understanding zoonotic reservoirs for hepatitis E virus (HEV). This study aimed to identify and characterize circulating zoonotic HEV in domestic pigs and wild boar to understand genotype frequencies, transmission dynamics, and associated human health burdens. Rectal swabs, feces, and liver samples from 415 pigs and 102 wild boars were collected across various farms and slaughterhouses in central and southern Vietnam and screened for HEV RNA using nested PCR. HEV RNA-positive samples underwent sanger sequencing and genotyping. Overall, 10% (n = 54/517) of samples were HEV RNA-positive, with wild boars exhibiting the highest HEV positivity rate at 25%, followed by domestic pigs at 7%. Southern Vietnam showed a higher HEV RNA positivity rate (20%) compared to central Vietnam (7%). Notably, rectal swabs demonstrated the highest positivity rate (15%), followed by feces (8%) and liver (4%). HEV-3a was the predominant genotype at 85%, followed by HEV-4b at 9% and HEV-3f at 6%. While HEV-3a was distributed across both central and southern Vietnam, HEV-3f was exclusively detected in central Vietnam, and HEV-4b was identified in wild boar in southern Vietnam. These findings underscore the substantial prevalence of HEV in wild boars, emphasizing their potential as crucial zoonotic reservoirs alongside domestic pigs. Further investigations involving occupationally exposed individuals in high-prevalence areas are warranted to evaluate the human health impact of zoonotic hepatitis E and inform preventive measures. Regular epidemiological studies are imperative for assessing the prevalence and transmission of zoonotic HEV infections among common reservoirs, thereby aiding in the prevention of spillover events within the community.

8.
Antibiotics (Basel) ; 13(7)2024 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-39061264

RESUMEN

Escherichia coli (E. coli) is one of the most common sources of infection in humans and animals. The emergence of E. coli which acquires resistance to various antibiotics has made treatment difficult. Bacteriophages can be considered promising agents to expand the options for the treatment of antibiotic-resistant bacteria. This study describes the isolation and characterization of Escherichia phage KIT06, which can infect E. coli resistant to the quinolone antibiotic nalidixic acid. Phage virions possess an icosahedral head that is 93 ± 8 nm in diameter and a contractile tail (116 ± 12 nm × 13 ± 5 nm). The phage was found to be stable under various thermal and pH conditions. A one-step growth curve showed that the latent time of the phage was 20 min, with a burst size of 28 particles per infected cell. Phage KIT06 infected 7 of 12 E. coli strains. It inhibited the growth of the host bacterium and nalidixic acid-resistant E. coli. The lipopolysaccharide and outer membrane proteins of E. coli, tsx and btuB, are phage receptors. Phage KIT06 is a new species of the genus Tequatrovirus with a genome of 167,059 bp consisting of 264 open reading frames (ORFs) that encode gene products related to morphogenesis, replication, regulation, and host lysis. The lack of genes encoding integrase or excisionase indicated that this phage was lytic. Thus, KIT06 could potentially be used to treat antibiotic-resistant E. coli using phage therapy. However, further studies are essential to understand its use in combination with other antimicrobial agents and its safe use in such applications.

9.
J Chem Phys ; 160(22)2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38856055

RESUMEN

The random-phase approximation (RPA) includes a subset of higher than second-order correlation-energy contributions, but stays in the same complexity class as the second-order Møller-Plesset perturbation theory (MP2) in both Gaussian-orbital and plane-wave codes. This makes RPA a promising ab initio electronic structure approach for the binding energies of molecular crystals. Still, some issues stand out in practical applications of RPA. Notably, compact clusters of nonpolar molecules are poorly described, and the interaction energies strongly depend on the reference single-determinant state. Using the many-body expansion of the binding energy of a crystal, we investigate those issues and the effect of beyond-RPA corrections. We find the beneficial effect of quartic-scaling exchange and non-ring coupled-cluster doubles corrections. The nonadditive interactions in compact trimers of molecules are improved by using the self-consistent Hartree-Fock orbitals instead of the usual Kohn-Sham states, but this kind of orbital input also leads to underestimated dimer energies. Overall, a substantial improvement over the RPA with a renormalized singles approach is possible at a modest quartic-scaling cost, which encourages further research into additional RPA corrections.

10.
Diagnostics (Basel) ; 14(8)2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38667466

RESUMEN

A laboratory-based lateral flow (LF) test that utilizes up-converting reporter particles (UCP) for ultrasensitive quantification of Schistosoma circulating anodic antigen (CAA) in urine is a well-accepted test to identify active infection. However, this UCP-LF CAA test requires sample pre-treatment steps not compatible with field applications. Flow, a new low-cost disposable, allows integration of large-volume pre-concentration of urine analytes and LF detection into a single field-deployable device. We assessed a prototype Flow-Schistosoma (Flow-S) device with an integrated UCP-LF CAA test strip, omitting all laboratory-based steps, to enable diagnosis of active Schistosoma infection in the field using urine. Flow-S is designed for large-volume (5-20 mL) urine, applying passive paper-based filtration and antibody-based CAA concentration. Samples tested for schistosome infection were collected from women of reproductive age living in a Tanzania region where S. haematobium infection is endemic. Fifteen negative and fifteen positive urine samples, selected based on CAA levels quantified in paired serum, were analyzed with the prototype Flow-S. The current Flow-S prototype, with an analytical lower detection limit of 1 pg CAA/mL, produced results correlated with the laboratory-based UCP-LF CAA test. Urine precipitates occurred in frozen banked samples and affected accurate quantification; however, this should not occur in fresh urine. Based on the findings of this study, Flow-S appears suitable to replace the urine pre-treatment required for the laboratory-based UCP-LF CAA test, thus allowing true field-based applications with fresh urine samples. The urine precipitates observed with frozen samples, though less important given the goal of testing fresh urines, warrant additional investigation to evaluate methods for mitigation. Flow-S devices permit testing of pooled urine samples with applications for population stratified testing. A field test with fresh urine samples, a further optimized Flow-S device, and larger statistical power has been scheduled.

12.
Endoscopy ; 56(4): 249-257, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38237633

RESUMEN

INTRODUCTION: Endoscopic ultrasound (EUS)-guided drainage of symptomatic pancreatic fluid collections (PFCs) using the Hot-Axios device has recently been associated with a significant risk of bleeding. This adverse event (AE) seems to occur less frequently with the use of a different device, the Spaxus stent. The aim of the current study was to compare the rates of bleeding between the two stents. METHODS: Patients admitted for treatment of PFCs by EUS plus lumen-apposing metal stent in 18 endoscopy referral centers between 10 July 2019 and 28 February 2022 were identified and their outcomes compared using a propensity-matching analysis. RESULTS: 363 patients were evaluated. After a 1-to-1 propensity score match, 264 patients were selected (132 per group). The technical and clinical success rates were comparable between the two groups. Significantly more bleeding requiring transfusion and/or intervention occurred in the Hot-Axios group than in the Spaxus group (6.8% vs. 1.5%; P = 0.03); stent type was a significant predictor of bleeding in both univariate and multivariate regression analyses (P = 0.03 and 0.04, respectively). Bleeding necessitating arterial embolization did not however differ significantly between the two groups (3.0% vs. 0%; P = 0.12). In addition, the Hot-Axios was associated with a significantly higher rate of overall AEs compared with the Spaxus stent (9.8% vs. 3.0%; P = 0.04). CONCLUSION: Our study showed that, in patients with PFCs, bleeding requiring transfusion and/or intervention occurred significantly more frequently with use of the Hot-Axios stent than with the Spaxus stent, although this was not the case for bleeding requiring embolization.


Asunto(s)
Páncreas , Enfermedades Pancreáticas , Humanos , Estudios Retrospectivos , Stents/efectos adversos , Endosonografía/efectos adversos , Drenaje/efectos adversos , Hemorragia/etiología , Endoscopía Gastrointestinal , Resultado del Tratamiento
13.
Commun Med (Lond) ; 3(1): 193, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-38129511

RESUMEN

INTRODUCTION: Public perception of the seriousness of the COVID-19 pandemic compared to six other major public health problems (alcoholism and drug use, HIV/AIDS, malaria, tuberculosis, lung cancer and respiratory diseases caused by air pollution and smoking, and water-borne diseases like diarrhea) is unclear. We designed a survey to examine this issue using YouGov's internet panels in seven middle-income countries in Africa, Asia, and Latin America in early 2022. METHODS: Respondents rank ordered the seriousness of the seven health problems using a repeated best-worst question format. Rank-ordered logit models allow comparisons within and across countries and assessment of covariates. RESULTS: In six of the seven countries, respondents perceived other respiratory illnesses to be a more serious problem than COVID-19. Only in Vietnam was COVID-19 ranked above other respiratory illnesses. Alcoholism and drug use was ranked the second most serious problem in the African countries. HIV/AIDS ranked relatively high in all countries. Covariates, particularly a COVID-19 knowledge scale, explained differences within countries; statistics about the pandemic were highly correlated with differences in COVID-19's perceived seriousness. CONCLUSIONS: People in the seven middle-income countries perceived COVID-19 to be serious (on par with HIV/AIDS) but not as serious as other respiratory illnesses. In the African countries, respondents perceived alcoholism and drug use as more serious than COVID-19. Our survey-based approach can be used to quickly understand how the threat of a newly emergent disease, like COVID-19, fits into the larger context of public perceptions of the seriousness of health problems.


We were curious what people in different countries thought about the seriousness of COVID-19 compared to other health problems. We designed a survey, and hired YouGov, a survey research firm, to administer it in seven countries in Africa, Asia, and Latin America in early 2022. Respondents answered the questions on their computer, tablets, or smart phones. Their answers revealed that in most countries respiratory illnesses were perceived to be a more serious problem than COVID-19. In Africa people felt that alcoholism and drug use were also more serious than COVID-19. These findings are important because they show that people still care about the health problems they were facing before the pandemic, which is useful information for healthcare providers.

14.
Molecules ; 28(22)2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-38005345

RESUMEN

Thickener, also known as a gelling agent, is a critical component of lubricating greases. The most critical property of thickener, temperature resistance, is determined by the molecular structure of the compounds. Currently, all high-temperature-resistant thickeners are based on 12-hydroxystearic acid, which is exclusively produced from castor oil. Since castor oil is also an important reagent for other processes, finding a sustainable alternative to 12-hydroxystearic acid has significant economic implications. This study synthesises an alternative thickener from abundant agricultural waste, cashew nut shell liquor (CNSL). The synthesis and separation procedure contains three steps: (i) forming and separating calcium anacardate by precipitation, (ii) forming and separating anacardic acid (iii) forming lithium anacardate. The obtained lithium anacardate can be used as a thickener for lubricating grease. It was found that the recovery of anacardic acid was around 80%. The optimal reaction temperature and time conditions for lithium anacardate were 100 °C and 1 h, respectively. The method provides an economical alternative to castor and other vegetable oils. The procedure presents a simple pathway to produce the precursor for the lubricating grease from agricultural waste. The first reaction step can be combined with the existing distillation of cashew nut shell processing. An effective application can promote CNSL to a sustainable feedstock for green chemistry. The process can also be combined with recycled lithium from the spent batteries to improve the sustainability of the battery industry.

15.
APL Bioeng ; 7(4): 046104, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37868708

RESUMEN

Vascular dysfunction is a common cause of cardiovascular diseases characterized by the narrowing and stiffening of arteries, such as atherosclerosis, restenosis, and hypertension. Arterial narrowing results from the aberrant proliferation of vascular smooth muscle cells (VSMCs) and their increased synthesis and deposition of extracellular matrix (ECM) proteins. These, in turn, are modulated by arterial stiffness, but the mechanism for this is not fully understood. We found that survivin is an important regulator of stiffness-mediated ECM synthesis and intracellular stiffness in VSMCs. Whole-transcriptome analysis and cell culture experiments showed that survivin expression is upregulated in injured femoral arteries in mice and in human VSMCs cultured on stiff fibronectin-coated hydrogels. Suppressed expression of survivin in human VSMCs significantly decreased the stiffness-mediated expression of ECM components related to arterial stiffening, such as collagen-I, fibronectin, and lysyl oxidase. By contrast, expression of these ECM proteins was rescued by ectopic expression of survivin in human VSMCs cultured on soft hydrogels. Interestingly, atomic force microscopy analysis showed that suppressed or ectopic expression of survivin decreases or increases intracellular stiffness, respectively. Furthermore, we observed that inhibiting Rac and Rho reduces survivin expression, elucidating a mechanical pathway connecting intracellular tension, mediated by Rac and Rho, to survivin induction. Finally, we found that survivin inhibition decreases FAK phosphorylation, indicating that survivin-dependent intracellular tension feeds back to maintain signaling through FAK. These findings suggest a novel mechanism by which survivin potentially modulates arterial stiffness.

16.
Sci Prog ; 106(3): 368504231195503, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37611190

RESUMEN

Ganoderma multipileum, a wood decay mushroom, was initially discovered and classified in Taiwan through the analysis of its morphology and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. In this study, we identified a mushroom associated with the dieback of Delonix regia (Boj. ex Hook.) Raf., a woody ornamental street tree in Vietnam, as Ganoderma multipileum. This classification was based on phylogenetic analysis of ITS, RPB2, and TEF1 sequences, as well as morphology assessment and scanning electron microscope observation of basidiospores. The phylogenetic analysis revealed that the specimens collected in Vietnam formed a monophyletic group of Ganoderma multipileum with a high bootstrap value and posterior probability (100%/1.00). Furthermore, the morphological features consistent with laccate Ganoderma, including a thin pileipellis composed of enlarged and bulbous hyphae, and the basidiomes exhibited two different phenotypes. Notably, scanning electron microscopy of the basidiospores revealed ovoid spores with numerous echinules, providing the first documented evidence of this characteristic for Ganoderma multipileum. This research represents the first recorded instance of Ganoderma multipileum in Vietnam associated with the dieback of Delonix regia.


Asunto(s)
Fabaceae , Ganoderma , Filogenia , Madera , Vietnam , Ganoderma/genética
17.
iScience ; 26(7): 107247, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37519899

RESUMEN

Loss of function of progranulin (PGRN), encoded by the granulin (GRN) gene, is implicated in several neurodegenerative diseases. Several therapeutics to boost PGRN levels are currently in clinical trials. However, it is difficult to test the efficacy of PGRN-enhancing drugs in mouse models due to the mild phenotypes of Grn-/- mice. Recently, mice deficient in both PGRN and TMEM106B were shown to develop severe motor deficits and pathology. Here, we show that intracerebral ventricle injection of PGRN-expressing AAV1/9 viruses partially rescues motor deficits, neuronal loss, glial activation, and lysosomal abnormalities in Tmem106b-/-Grn-/- mice. Widespread expression of PGRN is detected in both the brain and spinal cord for both AAV subtypes. However, AAV9 but not AAV1-mediated expression of PGRN results in high levels of PGRN in the serum. Together, these data support using the Tmem106b-/-Grn-/- mouse strain as a robust mouse model to determine the efficacy of PGRN-elevating therapeutics.

18.
Adv Respir Med ; 91(3): 268-277, 2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37366807

RESUMEN

BACKGROUND: In 2018, GOLD addressed the issues of genotypes associated with risk factors for COPD. The genome-wide association study (GWAS) demonstrated an association between COPD and several genetic variants of single nucleotide polymorphisms (SNPs) of the FAM13A gene with the risk of COPD. OBJECTIVE: To study the single nucleotide polymorphisms rs2869967 and rs17014601 of the FAM13A gene in chronic obstructive pulmonary disease. Subjects and research methods: 80 subjects diagnosed with COPD and 80 subjects determined not to have COPD according to GOLD 2020 criteria; the subjects were clinically examined, interviewed, and identified as possessing single nucleotide polymorphisms using the sanger sequencing method on whole blood samples. RESULTS: The male/female ratio of the patient group and the control group was 79/1 and 39/1, respectively. The percentages of C and T alleles of rs2869967 in COPD patients were 50.6% and 49.4%, respectively. The percentages of C and T alleles of rs17014601 in COPD patients were 31.9% and 68.1%, respectively. At rs17014601, the ratio values of alleles T and C in the disease group and the control group were markedly different, making them statistically reliable (p = 0.031). The rate of CT genotype in the group of patients was considerably higher than that of the control group. The TT homozygous genotype had a lower risk of COPD compared with the other genotypes in the dominant model (ORTT/(CC + CT) = 0.441; CI95% = 0.233-0.833); this difference was statistically significant (p = 0.012). CONCLUSIONS: With rs17014601, it is characteristic that the frequency of the T allele appears more than the C allele, and the CT heterozygous phenotype accounts for the highest proportion in rs17014601 and rs2869967 recorded in COPD patients. There is an association between the genetic variant of the SNP FAM13A-rs17014601 and the risk of COPD.


Asunto(s)
Polimorfismo de Nucleótido Simple , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Masculino , Femenino , Polimorfismo de Nucleótido Simple/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad/genética , Estudio de Asociación del Genoma Completo , Estudios de Casos y Controles , Vietnam , Frecuencia de los Genes , Proteínas Activadoras de GTPasa/genética
19.
Plant Dis ; 2023 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-37272045

RESUMEN

Pear (Pyrus communis) is an important fruit crop in the Netherlands, with a total production of 400,000 tons in 2020, and 'Conference' is the main pear cultivar that comprises 80% of total pear production area. In the Netherlands, pears are kept in controlled atmosphere cold storage (-0.5°C) up to 11 months after harvest. Calyx-end rot incidences of 1% to 5% were observed on 'Conference' pears from different orchards in surveys from 2019-2021 in packing houses in the Netherlands. Infections showed 1 to 3 cm brown necrosis. Lesions were round, slightly sunken and next to or including part of the calyx. To isolate the causal agent, fruit were rinsed with sterile water, lesions were sprayed with 70% ethanol until droplet runoff, the skin was removed aseptically with a scalpel, and tissue under the lesion was isolated and placed onto Potato Dextrose Agar (PDA) (Oxoid, UK). The PDA plates were incubated at 20°C in the dark, and hyphal tip isolates were transferred to fresh PDA plates. Colonies on PDA were rosy-whitish to peach-colored. Colonies grown on oat meal agar (OA) under UV light were peach to red color, aerial mycelium sparse, and produced a pink to salmon colored conidial matrix. Conidia were irregular-ellipsoidal to allantoid, smooth, hyaline and usually with one or several gutulles. Conidia were sometimes one septate and measured 15.2±2.8 x 4.0±0.7 µm (n =14), but mostly aseptate and measured 7.9±1.7 x 3.2±0.6 µm (n =100). The fungus was morphologically identical to Didymella macrostoma (syn. Phoma macrostoma) (Boerema et al. 2004; Hou et al. 2020). The identity of four representative isolates, WURR-206, WURR-223, WURR-227 and WURR-308, from affected pears from four orchards in the Netherlands, was determined by multilocus gene sequencing. To this end, genomic DNA was extracted using the LGC Mag Plant Kit (Berlin, Germany) in combination with the Kingfisher method (Waltham, MA). Sequences of the internal transcribed spacer (ITS) region of ribosomal DNA, the large-subunit rRNA (LSU) region, partial sequences of beta-tubulin (TUB) and the translation elongation factor 1-alpha (TEF1) gene region were amplified with primers ITS1/ITS4 (White et al. 1990), LROR/LR5 (Vilgalys and Hester 1990), Btub2Fd/Btub4Rd (Woudenberg et al. 2009) and EF1-983F/EF1-1567R (Rehner and Buckley 2005), respectively. Sequences were deposited under GenBank accession numbers ON077588-ON077591 (ITS), ON113487-ON113490 (LSU), ON098515-ON098518 (TUB) and ON098519-ON098522 (TEF1). MegaBLAST analysis revealed that the ITS, LSU, TUB sequences matched with 100% identity to culture collection sequences of Didymella macrostoma in GenBank MH854841 (ITS), MH866341 (LSU), MN983895 (TUB). The TEF1 sequences matched with 99.7% identity to TEF sequence of Didymella macrostoma MT454020. Subsequently, Koch's postulates were performed on 10 'Conference' pears per isolate (WURR-206, WURR-223, WURR-227 and WURR-308). Fruits wiped with 70% ethanol were inoculated in pathogenicity tests with an agar disk (5 mm diameter) of D. macrostoma prepared from the actively growing edge of 14-day-old cultures grown on PDA. Inoculated fruits were sealed in plastic bags and were incubated in darkness at 20°C. Typical symptoms appeared 7-10 days after inoculation on all pears. PDA-only controls remained symptomless. Fungal colonies isolated from the lesions and cultured on PDA morphologically resembled the original isolate from the infected pears. The identity of the re-isolations was confirmed as D. macrostoma by sequencing, thus completing Koch's postulates. To the best of our knowledge, this is the first report of D. macrostoma causing calyx-end rot of pears. The identification of this causal agent is important knowledge necessary for developing control measures for postharvest diseases of pear.

20.
J Chem Phys ; 158(14): 144119, 2023 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-37061498

RESUMEN

The relative energies of different phases or polymorphs of molecular solids can be small, less than a kilojoule/mol. A reliable description of such energy differences requires high-quality treatment of electron correlations, typically beyond that achievable by routinely applicable density functional theory (DFT) approximations. At the same time, high-level wave function theory is currently too computationally expensive. Methods employing an intermediate level of approximations, such as Møller-Plesset (MP) perturbation theory and the random phase approximation (RPA), are potentially useful. However, their development and application for molecular solids has been impeded by the scarcity of necessary benchmark data for these systems. In this work, we employ the coupled-cluster method with singles, doubles, and perturbative triples to obtain a reference-quality many-body expansion of the binding energy of four crystalline hydrocarbons with a varying π-electron character: ethane, ethene, and cubic and orthorhombic forms of acetylene. The binding energy is resolved into explicit dimer, trimer, and tetramer contributions, which facilitates the analysis of errors in the approximate approaches. With the newly generated benchmark data, we test the accuracy of MP2 and non-self-consistent RPA. We find that both of the methods poorly describe the non-additive many-body interactions in closely packed clusters. Using different DFT input states for RPA leads to similar total binding energies, but the many-body components strongly depend on the choice of the exchange-correlation functional.

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