Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 126
Filter
1.
J Surg Case Rep ; 2024(7): rjae460, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39005640

ABSTRACT

Duplication cysts are rare congenital abnormalities of the alimentary tract, typically manifesting symptoms in the first 2 years but uncommon in adults. Medical data on duplication cysts is scarce in Vietnam's Mekong Delta region. These two adult cases aim to provide fundamental knowledge, clinical characteristics, diagnosis, risks, complications, surgical and observational treatment methods, and future bilateral tumor research. Case 1: A 21-year-old male with intestinal obstruction symptoms. Computed tomography (CT)-scan revealed a strangulated small bowel obstruction with ischemia. Laparotomy discovered a twisted ileal duplication cyst causing necrosis in ~30 cm of the small intestine. Case 2: A 34-year-old woman hospitalized for right lower quadrant pain. CT-scan showed a cystic structure protruding into the ascending colon lumen. She underwent a laparoscopic right hemicolectomy, and an ascending colonic cyst was found in the specimen. Conclusions: Duplication cysts are rare anomalies, especially in adults. Comprehending and acquiring knowledge ensures prompt diagnosis and appropriate treatment.

2.
Chemosphere ; 362: 142654, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38901705

ABSTRACT

Clean water is an integral part of industries, agricultural activities and human life, but water contamination by toxic dyes, heavy metals, and oil spills is increasingly serious in the world. Aerogels with unique properties such as highly porous and extremely low density, tunable surface modification, excellent reusability, and thermal stability can contribute to addressing these issues. Thanks to high purity, biocompatibility and biodegradability, bacterial cellulose can be an ideal precursor source to produce aerogels. Here, we review the modification, regeneration, and applications of bacterial cellulose-based aerogels for water treatment. The modification of bacterial cellulose-based aerogels undergoes coating of hydrophobic agents, carbonization, and incorporation with other materials, e.g., ZIF-67, graphene oxide, nanoparticles, polyaniline. We emphasized features of modified aerogels on porosity, hydrophobicity, density, surface chemistry, and regeneration. Although major limits are relevant to the use of toxic coating agents, difficulty in bacterial culture, and production cost, the bacterial cellulose aerogels can obtain high performance for water treatment, particularly, catastrophic oil spills.

3.
Rev Sci Instrum ; 95(5)2024 May 01.
Article in English | MEDLINE | ID: mdl-38717277

ABSTRACT

Here a sealing-style x-ray photoelectron spectroscopy study of the surface of a 1.0 wt. %Ni/TiO2 nanoparticle catalyst in a flowing mixture of CO and O2 at 1 bar was performed with a graphene membrane-sealed Si3N4 window-based miniature cell. We report the details on how a commercial Si3N4 window is modified before assembling a graphene membrane, how single-layer graphene membranes are transferred from their metal supports to the modified Si3N4 window, how a modified Si3N4 window covered with a double-layer graphene membrane is assembled onto a blank cell cap, how a nanoparticle catalyst is introduced to the cell cap and then the cell cap is installed onto a cell body to form a complete reaction cell, and how a complete cell is interfaced with a high vacuum chamber of an XPS system before an XPS study of 1.0 wt. %Ni/TiO2 catalyst surface in a flowing mixture for 0.2 bar CO and 0.8 bar O2 is performed. How the characterization of a catalyst using this type of graphene membrane-sealed Si3N4 window-based miniature cell is relevant to the finding of the actual surface chemistry of a catalyst during catalysis is discussed.

4.
Microb Genom ; 10(5)2024 May.
Article in English | MEDLINE | ID: mdl-38739115

ABSTRACT

Aeromonas spp. are commonly found in the aquatic environment and have been responsible for motile Aeromonas septicemia (MAS) in striped catfish, resulting in significant economic loss. These organisms also cause a range of opportunistic infections in humans with compromised immune systems. Here, we conducted a genomic investigation of 87 Aeromonas isolates derived from diseased catfish, healthy catfish and environmental water in catfish farms affected by MAS outbreaks in eight provinces in Mekong Delta (years: 2012-2022), together with 25 isolates from humans with bloodstream infections (years: 2010-2020). Genomics-based typing method precisely delineated Aeromonas species while traditional methods such as aerA PCR and MALDI-TOF were unable identify A. dhakensis. A. dhakensis was found to be more prevalent than A. hydrophila in both diseased catfish and human infections. A. dhakensis sequence type (ST) 656 followed by A. hydrophila ST251 were the predominant virulent species-lineages in diseased catfish (43.7 and 20.7 %, respectively), while diverse STs were found in humans with bloodstream infections. There was evidence of widespread transmission of ST656 and ST251 on striped catfish in the Mekong Delta region. ST656 and ST251 isolates carried a significantly higher number of acquired antimicrobial resistance (AMR) genes and virulence factors in comparison to other STs. They, however, exhibited several distinctions in key virulence factors (i.e. lack of type IV pili and enterotoxin ast in A. dhakensis), AMR genes (i.e. presence of imiH carbapenemase in A. dhakensis), and accessory gene content. To uncover potential conserved proteins of Aeromonas spp. for vaccine development, pangenome analysis has unveiled 2202 core genes between ST656 and ST251, of which 78 proteins were in either outer membrane or extracellular proteins. Our study represents one of the first genomic investigations of the species distribution, genetic landscape, and epidemiology of Aeromonas in diseased catfish and human infections in Vietnam. The emergence of antimicrobial resistant and virulent A. dhakensis strains underscores the needs of enhanced genomic surveillance and strengthening vaccine research and development in preventing Aeromonas diseases in catfish and humans, and the search for potential vaccine candidates could focus on Aeromonas core genes encoded for membrane and secreted proteins.


Subject(s)
Aeromonas , Catfishes , Fish Diseases , Gram-Negative Bacterial Infections , Sepsis , Animals , Catfishes/microbiology , Vietnam/epidemiology , Aeromonas/genetics , Aeromonas/isolation & purification , Aeromonas/classification , Aeromonas/pathogenicity , Gram-Negative Bacterial Infections/microbiology , Gram-Negative Bacterial Infections/veterinary , Gram-Negative Bacterial Infections/epidemiology , Humans , Sepsis/microbiology , Sepsis/veterinary , Sepsis/epidemiology , Fish Diseases/microbiology , Phylogeny , Genomics , Genome, Bacterial , Virulence Factors/genetics , Anti-Bacterial Agents/pharmacology
5.
Cureus ; 16(4): e59337, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38817523

ABSTRACT

INTRODUCTION: The mandibular foramen (MnF) and the mental foramen (MF) are essential anatomical landmarks that should be considered before any surgical procedures in the mandible. This study aimed to investigate the characteristics of the MnF and MF in relation to adjacent anatomical structures, as well as age and gender differences, using cone beam computed tomography (CBCT) projections. METHODS: The study was conducted from August 2023 to January 2024 at the Can Tho University of Medicine and Pharmacy Hospital, Vietnam. In this retrospective study, 50 CBCT images of Vietnamese patients were randomly taken for various clinical purposes. Furthermore, relevant data, such as gender and age groups, were selected to evaluate the correlations, along with specific inclusion criteria. Patients within the age range of 18-69 with a symmetrical mandible were included. RESULTS: The distance of the MnF-MN was 29.6±5.0 mm (right) and 30.1±4.6 mm (left) in males and 25.0±4.2 mm (right) and 26.3±5.0 mm (left) in females. The distance of the MnF-posterior border of the ramus (P) was 16.2±3.6 mm (right) and 15.0±2.3 mm (left) in males. For females, it was 17.1±2.9 mm (right) and 13.8±1.7 mm (left). The distance of the MF-body mandible (MB) was 15.4±2.4 mm (right) and 15.6±2.0 mm (left) in males and 14.0±2.1 mm (right) and 14.3±1.6 mm (left) in females. The distance of the MF-mandibular midline (MM) was 27.0±2.6 mm (right) and 27.0±2.9 mm (left) in males and 25.3±2.0 mm (right) and 25.1±2.2 mm (left) in females. These distances showed statistically significant differences depending on gender (P<0.05). CONCLUSION: It can be said that CBCT provides comprehensive information about the MnF and the MF for dentists in research and clinical practice.

6.
Int Urol Nephrol ; 2024 May 27.
Article in English | MEDLINE | ID: mdl-38797767

ABSTRACT

PURPOSE: The aim of this study was to assess the long-term outcomes of retroperitoneoscopic one-trocar-assisted pyeloplasty (OTAP) for ureteropelvic junction obstruction (UPJO) in children. METHODS: This retrospective analysis included 70 pediatric cases, all under the age of 5, diagnosed with UPJO and treated with the OTAP technique between May 2011 and June 2013 by a single surgeon. A single 10 mm operative scope with a 5 mm working channel was utilized to mobilize the ureteropelvic junction (UPJ) and exteriorize it through the trocar insertion site. Subsequently, conventional Anderson-Hynes dismembered pyeloplasty was conducted extracorporeally. Patient's demographics, operative time, hospital stay, complications, and success rate were evaluated. RESULTS: Seventy pediatric patients (65 males and 5 females) underwent OTAP, with ages at the time of operation ranging from 1 month to 5 years (mean = 22.6 ± 18.6 months). The mean operative time was 74.8 ± 15.2 min. There was a significant reduction in the mean renal pelvis size from 34.3 ± 8.1 mm preoperatively to 13.8 ± 4.7 mm postoperatively (p < 0.05). Moreover, the mean differential renal function (DRF) increased from 47.9 ± 9.8% preoperatively to 51.2 ± 5.9% postoperatively (p < 0.05). All patients experienced an uneventful postoperative recovery, with a median hospital stay of 3.4 days. The success rate was 95.7%, with a median follow-up time of 75 months (range: 6-125 months). CONCLUSION: OTAP is a safe and feasible minimally invasive technique to correct ureteropelvic junction obstruction in children. It could be considered as a treatment of choice for children under the age of 5 as it combines the advantages of open and retroperitoneoscopic pyeloplasty and presents excellent long-term outcomes. TRIAL REGISTRATION NUMBER: NCT06349161 April 4th, 2024, retrospectively registered.

7.
Environ Res ; 255: 119144, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38751006

ABSTRACT

Currently, plastic waste and antibiotic wastewater are two of the most critical environmental problems, calling for urgent measures to take. A waste-to-wealth strategy for the conversion of polyethylene terephthalate (PET) plastic bottles into value-added materials such as carbon composite is highly recommended to clean wastewater contaminated by antibiotics. Inspired by this idea, we develop a novel PET-AC-ZFO composite by incorporating PET plastic-derived KOH-activated carbon (AC) with ZnFe2O4 (ZFO) particles for adsorptive removal of tetracycline (TTC). PET-derived carbon (PET-C), KOH-activated PET-derived carbon (PET-AC), and PET-AC-ZFO were characterized using physicochemical analyses. Central composite design (CCD) was used to obtain a quadratic model by TTC concentration (K), adsorbent dosage (L), and pH (M). PET-AC-ZFO possessed micropores (d ≈ 2 nm) and exceptionally high surface area of 1110 m2 g-1. Nearly 90% TTC could be removed by PET-AC-ZFO composite. Bangham kinetic and Langmuir isotherm were two most fitted models. Theoretical maximum TTC adsorption capacity was 45.1 mg g-1. This study suggested the role of hydrogen bonds, pore-filling interactions, and π-π interactions as the main interactions of the adsorption process. Thus, a strategy for conversion of PET bottles into PET-AC-ZFO can contribute to both plastic recycling and antibiotic wastewater mitigation.


Subject(s)
Anti-Bacterial Agents , Carbon , Tetracycline , Water Pollutants, Chemical , Adsorption , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/analysis , Tetracycline/chemistry , Anti-Bacterial Agents/chemistry , Carbon/chemistry , Plastics/chemistry , Water Purification/methods , Wastewater/chemistry , Polyethylene Terephthalates/chemistry
8.
Chemosphere ; 358: 142087, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38657696

ABSTRACT

Bidens pilosa is classified as an invasive plant and has become a problematic weed to many agricultural crops. This species strongly germinates, grows and reproduces and competing for nutrients with local plants. To lessen the influence of Bidens pilosa, therefore, converting this harmful species into carbon materials as adsorbents in harm-to-wealth and valorization strategies is required. Here, we synthesized a series of magnetic composites based on MFe2O4 (M = Ni, Co, Zn, Fe) supported on porous carbon (MFOAC) derived from Bidens pilosa by a facile hydrothermal method. The Bidens pilosa carbon was initially activated by condensed H3PO4 to increase the surface chemistry. We observed that porous carbon loaded NiFe2O4 (NFOAC) reached the highest surface area (795.7 m2 g-1), followed by CoFe2O4/AC (449.1 m2 g-1), Fe3O4/AC (426.1 m2 g-1), ZnFe2O4/AC (409.5 m2 g-1). Morphological results showed nanoparticles were well-dispersed on the surface of carbon. RhB, MO, and MR dyes were used as adsorbate to test the adsorption by MFOAC. Effect of time (0-360 min), concentration (5-50 mg L-1), dosage (0.05-0.2 g L-1), and pH (3-9) on dyes adsorption onto MFOAC was investigated. It was found that NFOAC obtained the highest maximum adsorption capacity against dyes, RhB (107.96 mg g-1) < MO (148.05 mg g-1) < MR (153.1 mg g-1). Several mechanisms such as H bonding, π-π stacking, cation-π interaction, and electrostatic interaction were suggested. With sufficient stability and capacity, NFOAC can be used as potential adsorbent for real water treatment systems.


Subject(s)
Bidens , Carbon , Coloring Agents , Ferric Compounds , Adsorption , Bidens/chemistry , Porosity , Carbon/chemistry , Ferric Compounds/chemistry , Coloring Agents/chemistry , Nickel/chemistry , Water Pollutants, Chemical/chemistry , Zinc/chemistry , Plant Weeds/drug effects , Cobalt/chemistry
9.
Article in English | MEDLINE | ID: mdl-38468003

ABSTRACT

The presence of stable and hazardous organic dyes in industrial effluents poses significant risks to both public health and the environment. Activated carbons and biochars are widely used adsorbents for removal of these pollutants, but they often have several disadvantages such as poor recoverability and inseparability from water in the post-adsorption process. Incorporating a magnetic component into activated carbons can address these drawbacks. This study aims to optimizing the production of NiFe2O4-loaded activated carbon (NiFe2O4@AC) derived from a Bidens pilosa biomass source through a hydrothermal method for the adsorption of Rhodamine B (RhB), methyl orange (MO), and methyl red (MR) dyes. Response surface methodology (RSM) and Box-Behnken design (BBD) were applied to analyze the key synthesis factors such as NiFe2O4 loading percentage (10-50%), hydrothermal temperature (120-180 °C), and reaction time (6-18 h). The optimized condition was found at a NiFe2O4 loading of 19.93%, a temperature of 135.55 °C, and a reaction time of 16.54 h. The optimum NiFe2O4@AC demonstrated excellent sorption efficiencies of higher than 92.98-97.10% against all three dyes. This adsorbent was characterized, exhibiting a well-developed porous structure with a high surface area of 973.5 m2 g-1. Kinetic and isotherm were studied with the best fit of pseudo-second-order, and Freundlich or Temkin. Qmax values were determined to be 204.07, 266.16, and 177.70 mg g-1 for RhB, MO, and MR, respectively. By selecting HCl as an elution, NiFe2O4@AC could be efficiently reused for at least 4 cycles. Thus, the Bidens pilosa-derived NiFe2O4@AC can be a promising material for effective and recyclable removal of dye pollutants from wastewater.

10.
Am J Physiol Renal Physiol ; 326(1): F39-F56, 2024 01 01.
Article in English | MEDLINE | ID: mdl-37881876

ABSTRACT

The with-no-lysine kinase 4 (WNK4)-sterile 20/SPS-1-related proline/alanine-rich kinase (SPAK)/oxidative stress-responsive kinase 1 (OSR1) pathway mediates activating phosphorylation of the furosemide-sensitive Na+-K+-2Cl- cotransporter (NKCC2) and the thiazide-sensitive NaCl cotransporter (NCC). The commonly used pT96/pT101-pNKCC2 antibody cross-reacts with pT53-NCC in mice on the C57BL/6 background due to a five amino acid deletion. We generated a new C57BL/6-specific pNKCC2 antibody (anti-pT96-NKCC2) and tested the hypothesis that the WNK4-SPAK/OSR1 pathway strongly regulates the phosphorylation of NCC but not NKCC2. In C57BL/6 mice, anti-pT96-NKCC2 detected pNKCC2 and did not cross-react with NCC. Abundances of pT96-NKCC2 and pT53-NCC were evaluated in Wnk4-/-, Osr1-/-, Spak-/-, and Osr1-/-/Spak-/- mice and in several models of the disease familial hyperkalemic hypertension (FHHt) in which the CUL3-KLHL3 ubiquitin ligase complex that promotes WNK4 degradation is dysregulated (Cul3+/-/Δ9, Klhl3-/-, and Klhl3R528H/R528H). All mice were on the C57BL/6 background. In Wnk4-/- mice, pT53-NCC was almost absent but pT96-NKCC2 was only slightly lower. pT53-NCC was almost absent in Spak-/- and Osr1-/-/Spak-/- mice, but pT96-NKCC2 abundance did not differ from controls. pT96-NKCC2/total NKCC2 was slightly lower in Osr1-/- and Osr1-/-/Spak-/- mice. WNK4 expression colocalized not only with NCC but also with NKCC2 in Klhl3-/- mice, but pT96-NKCC2 abundance was unchanged. Consistent with this, furosemide-induced urinary Na+ excretion following thiazide treatment was similar between Klhl3-/- and controls. pT96-NKCC2 abundance was also unchanged in the other FHHt mouse models. Our data show that disruption of the WNK4-SPAK/OSR1 pathway only mildly affects NKCC2 phosphorylation, suggesting a role for other kinases in NKCC2 activation. In FHHt models NKCC2 phosphorylation is unchanged despite higher WNK4 abundance, explaining the thiazide sensitivity of FHHt.NEW & NOTEWORTHY The renal cation cotransporters NCC and NKCC2 are activated following phosphorylation mediated by the WNK4-SPAK/OSR1 pathway. While disruption of this pathway strongly affects NCC activity, effects on NKCC2 activity are unclear since the commonly used phospho-NKCC2 antibody was recently reported to cross-react with phospho-NCC in mice on the C57BL/6 background. Using a new phospho-NKCC2 antibody specific for C57BL/6, we show that inhibition or activation of the WNK4-SPAK/OSR1 pathway in mice only mildly affects NKCC2 phosphorylation.


Subject(s)
Protein Serine-Threonine Kinases , Pseudohypoaldosteronism , Animals , Mice , Furosemide , Mice, Inbred C57BL , Phosphorylation , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Pseudohypoaldosteronism/genetics , Pseudohypoaldosteronism/metabolism , Solute Carrier Family 12, Member 3/genetics , Solute Carrier Family 12, Member 3/metabolism , Thiazides
11.
Urol Case Rep ; 50: 102519, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37593360

ABSTRACT

Pelvic arteriovenous malformation is a rare vascular abnormality, espescially in male patients, and is difficult to treat because of its nature supplied by multiple arterial feeders. We report a 70-year-old male patient admitted due to symptoms of benign prostatic hyperplasia. Ultrasound was performed initially, and no other abnormalities were found other than an enlarged prostate. CT scan later demonstrated a pelvic arteriovenous malformation adjacent to the prostate, with multiple arterial feeders from the right internal iliac artery. Angiography confirmed the diagnosis, and transaterial embolization was successfully done. The symptoms disappeared several days later, and the patient remained asymptompmatic during follow-up.

12.
Nat Mater ; 22(10): 1261-1272, 2023 10.
Article in English | MEDLINE | ID: mdl-37592029

ABSTRACT

Nanoparticles enter tumours through endothelial cells, gaps or other mechanisms, but how they exit is unclear. The current paradigm states that collapsed tumour lymphatic vessels impair the exit of nanoparticles and lead to enhanced retention. Here we show that nanoparticles exit the tumour through the lymphatic vessels within or surrounding the tumour. The dominant lymphatic exit mechanism depends on the nanoparticle size. Nanoparticles that exit the tumour through the lymphatics are returned to the blood system, allowing them to recirculate and interact with the tumour in another pass. Our results enable us to define a mechanism of nanoparticle delivery to solid tumours alternative to the enhanced permeability and retention effect. We call this mechanism the active transport and retention principle. This delivery principle provides a new framework to engineer nanomedicines for cancer treatment and detection.


Subject(s)
Lymphatic Vessels , Nanoparticles , Neoplasms , Humans , Endothelial Cells , Neoplasms/drug therapy , Drug Delivery Systems
13.
Zootaxa ; 5318(1): 130-144, 2023 Jul 18.
Article in English | MEDLINE | ID: mdl-37518394

ABSTRACT

We describe a new species of Dendrelaphis from the coastal area in southern Vietnam based on morphological data and nucleotide sequences from one partial mitochondrial gene (Cytb). Dendrelaphis binhi sp. nov. is diagnosed by the following morphological characters: body scale rows 13 at neck and midbody, 9-11 before vent; vertebral scale row feebly enlarged; ventrals 154-158 in males and 161-170 in females; subcaudals 95-106 in males and 95-102 in females; one supralabial touching the eye; 18 or 19 maxillary teeth; hemipenis spinose, reaching 10th or 11th SC, with a slender papilla; cloacal plate divided; dorsum dark brown; and a white stripe along the lower flank. The new species differs from its congeners by an uncorrected p-distance in Cytb sequences of at least 8.1%.


Subject(s)
Colubridae , Lizards , Male , Female , Animals , Vietnam , Animal Structures/anatomy & histology , Animal Distribution , Phylogeny
14.
Nano Lett ; 23(15): 7197-7205, 2023 08 09.
Article in English | MEDLINE | ID: mdl-37506224

ABSTRACT

Nanobio interaction studies have generated a significant amount of data. An important next step is to organize the data and design computational techniques to analyze the nanobio interactions. Here we developed a computational technique to correlate the nanoparticle spatial distribution within heterogeneous solid tumors. This approach led to greater than 88% predictive accuracy of nanoparticle location within a tumor tissue. This proof-of-concept study shows that tumor heterogeneity might be defined computationally by the patterns of biological structures within the tissue, enabling the identification of tumor patterns for nanoparticle accumulation.


Subject(s)
Nanoparticles , Neoplasms , Humans , Nanoparticles/chemistry
15.
Bioresour Technol ; 384: 129315, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37321309

ABSTRACT

Poly(3-hydroxybutyrate) (PHB) is a prominent bio-plastic and recognized as the potential replacement of petroleum-derived plastics. To make PHB cost-effective, the production scheme based on crude glycerol was developed using Escherichia coli. The heterogeneous synthesis pathway of PHB was introduced into the E. coli strain capable of efficiently utilizing glycerol. The central metabolism that links to the synthesis of acetyl-CoA and NADPH was further reprogrammed to improve the PHB production. Key genes were targeted for manipulation, involving those in glycolysis, the pentose phosphate pathway, and the tricarboxylic cycle. As a result, the engineered strain gained a 22-fold increase in the PHB titer. Finally, the fed-batch fermentation was conducted with the producer strain to give the PHB titer, content, and productivity reaching 36.3 ± 3.0 g/L, 66.5 ± 2.8%, and 1.2 ± 0.1 g/L/h, respectively. The PHB yield on crude glycerol accounts for 0.3 g/g. The result indicates that the technology platform as developed is promising for the production of bio-plastics.


Subject(s)
Escherichia coli , Glycerol , 3-Hydroxybutyric Acid/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Glycerol/metabolism , Hydroxybutyrates/metabolism , Polyesters/metabolism , Plastics/metabolism
16.
Toxicon ; 230: 107173, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37211058

ABSTRACT

Greater levels of insect resistance and constraints on the use of current pesticides have recently led to increased crop losses in agricultural production. Further, the health and environmental impacts of pesticides now restrict their application. Biologics based on peptides are gaining popularity as efficient crop protection agents with low environmental toxicity. Cysteine-rich peptides (whether originated from venoms or plant defense substances) are chemically stable and effective as insecticides in agricultural applications. Cysteine-rich peptides fulfill the stability and efficacy requirements for commercial uses and provide an environmentally benign alternative to small-molecule insecticides. In this article, cysteine-rich insecticidal peptide classes identified from plants and venoms will be highlighted, focusing on their structural stability, bioactivity and production.


Subject(s)
Insecticides , Animals , Insecticides/chemistry , Cysteine , Peptides/chemistry , Insecta , Venoms
17.
Rev Sci Instrum ; 94(5)2023 May 01.
Article in English | MEDLINE | ID: mdl-37255372

ABSTRACT

Numerous important catalytic reactions, such as Fischer-Tropsch synthesis (FTS), are performed under harsh conditions in terms of high temperature of a catalyst in a mixture of reactants at a high pressure. There has been a lack of an intrinsic correlation between a catalytic performance and its corresponding catalyst structure due to the unavailable information on the authentic structure of the catalyst during catalysis under a high-temperature high-pressure (HTHP) condition. Here, we report in situ/operando studies of Co catalysts during catalysis under HTHP conditions using x-ray absorption spectroscopy (XAS). A high-temperature high-pressure catalysis-XAS (HTHP Catalysis-XAS) system using a thin, small quartz or beryllium tube as the reactor was built for in situ/operando characterization of high-energy absorption edges of 4d transition metals or low-energy absorption edges of 3d/4d transition metals under high-temperature high-pressure conditions, respectively. This reactor can be used for HTHP catalysis performed at a temperature of up to 550 °C and a gas pressure of up to 60 bars for uncovering the chemical states and coordination environments of metal atoms of these catalysts during HTHP catalysis. The capability of collecting XAS data during HTHP catalysis was confirmed through tests at 400oC in the mixture of 20 bar mixture of reactants at beamline endstation. The operando studies of Ru catalyst particles under Fischer-Tropsch catalytic conditions with extended x-ray absorption fine structure spectroscopy revealed a restructuring of the Ru catalyst at 250 °C in the mixture of 6 bars CO and 12 bars H2 during FTS (30 ml/min), which was not observed at 300 °C in 1 bar H2 (20 ml/min). This observation suggests new chemistry for metal catalysts under HTHP condition inaccessible due to a lack of applicable characterizations. These tests confirmed the function of this HTHP Catalysis-XAS system for in situ/operando characterizations of catalysts during HTHP catalysis.

18.
Nature ; 618(7964): 333-341, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37165194

ABSTRACT

Metastatic cancer remains an almost inevitably lethal disease1-3. A better understanding of disease progression and response to therapies therefore remains of utmost importance. Here we characterize the genomic differences between early-stage untreated primary tumours and late-stage treated metastatic tumours using a harmonized pan-cancer analysis (or reanalysis) of two unpaired primary4 and metastatic5 cohorts of 7,108 whole-genome-sequenced tumours. Metastatic tumours in general have a lower intratumour heterogeneity and a conserved karyotype, displaying only a modest increase in mutations, although frequencies of structural variants are elevated overall. Furthermore, highly variable tumour-specific contributions of mutational footprints of endogenous (for example, SBS1 and APOBEC) and exogenous mutational processes (for example, platinum treatment) are present. The majority of cancer types had either moderate genomic differences (for example, lung adenocarcinoma) or highly consistent genomic portraits (for example, ovarian serous carcinoma) when comparing early-stage and late-stage disease. Breast, prostate, thyroid and kidney renal clear cell carcinomas and pancreatic neuroendocrine tumours are clear exceptions to the rule, displaying an extensive transformation of their genomic landscape in advanced stages. Exposure to treatment further scars the tumour genome and introduces an evolutionary bottleneck that selects for known therapy-resistant drivers in approximately half of treated patients. Our data showcase the potential of pan-cancer whole-genome analysis to identify distinctive features of late-stage tumours and provide a valuable resource to further investigate the biological basis of cancer and resistance to therapies.


Subject(s)
Genome, Human , Genomics , Neoplasm Metastasis , Neoplasms , Female , Humans , Male , Disease Progression , Mutation , Neoplasm Metastasis/genetics , Neoplasms/genetics , Genome, Human/genetics , Cohort Studies , Karyotyping , APOBEC Deaminases/metabolism
19.
Amino Acids ; 55(6): 713-729, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37142771

ABSTRACT

Cyclotides are plant peptides characterized with a head-to-tail cyclized backbone and three interlocking disulfide bonds, known as a cyclic cysteine knot. Despite the variations in cyclotides peptide sequences, this core structure is conserved, underlying their most useful feature: stability against thermal and chemical breakdown. Cyclotides are the only natural peptides known to date that are orally bioavailable and able to cross cell membranes. Cyclotides also display bioactivities that have been exploited and expanded to develop as potential therapeutic reagents for a wide range of conditions (e.g., HIV, inflammatory conditions, multiple sclerosis, etc.). As such, in vitro production of cyclotides is of the utmost importance since it could assist further research on this peptide class, specifically the structure-activity relationship and its mechanism of action. The information obtained could be utilized to assist drug development and optimization. Here, we discuss several strategies for the synthesis of cyclotides using both chemical and biological routes.


Subject(s)
Cyclotides , Cyclotides/pharmacology , Cyclotides/therapeutic use , Cyclotides/chemistry , Amino Acid Sequence , Plants/metabolism , Cysteine , Structure-Activity Relationship
20.
J Am Chem Soc ; 145(1): 392-401, 2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36548635

ABSTRACT

Heterogeneous catalysis is key for chemical transformations. Understanding how catalysts' active sites dynamically evolve at the atomic scale under reaction conditions is a prerequisite for accurately determining catalytic mechanisms and predictably developing catalysts. We combine in situ time-dependent scanning tunneling microscopy observations and machine-learning-accelerated first-principles atomistic simulations to uncover the mechanism of restructuring of Pt catalysts under a pressure of carbon monoxide (CO). We show that a high CO coverage at a Pt step edge triggers the formation of atomic protrusions of low-coordination Pt atoms, which then detach from the step edge to create sub-nano-islands on the terraces, where under-coordinated sites are stabilized by the CO adsorbates. The fast and accurate machine-learning potential is key to enabling the exploration of tens of thousands of configurations for the CO-covered restructuring catalyst. These studies open an avenue to achieve an atomic-scale understanding of the structural dynamics of more complex metal nanoparticle catalysts under reaction conditions.

SELECTION OF CITATIONS
SEARCH DETAIL
...