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Polymers Jun 2024The freeze-drying of biopolymers presents a fresh option with greater potential for application in soil subgrade stabilization. A freeze-dried combination of β-glucan...
The freeze-drying of biopolymers presents a fresh option with greater potential for application in soil subgrade stabilization. A freeze-dried combination of β-glucan (BG) and γ-poly-glutamic acid (GPA) biopolymers was used to treat low compressible clay (CL) and low compressible silt (ML) soils in dosages of 0.5%, 1%, 1.5%, and 2%. The California bearing ratio (CBR) test for the treated specimens was performed under three curing conditions: (i) thermal curing at 60 °C, (ii) air-curing for seven days followed by submergence for 4 days, and (iii) no curing, i.e., tested immediately after mixing. To investigate the influence of shear strength on the freeze-dried biopolymer-stabilized soil specimens and their variations with aging, unconfined compressive strength (UCS) tests were conducted after thermal curing at 60 °C for 3 days, 7 days, and 7 days of thermal curing followed by 21 days of air curing. The maximum CBR of 125.3% was observed for thermally cured CL and a minimum CBR of 6.1% was observed under soaked curing conditions for ML soils. Scanning electron microscopy (SEM), infrared spectroscopy, average particle size, permeability, and adsorption tests revealed the pore filling, biopolymer adsorption and coating on the soil surface, and agglomeration of the soil along with the presence of hydrogen bonds, covalent amide bonds, and Van der Waals forces that contributed to the stiffening of the stabilized soil. Using three-dimensional (3D) finite element analysis (FEA) and layered elastic analysis (LEA), a mechanistic-empirical pavement design was carried out for the stabilized soil and a design thickness catalog was prepared for the maximum CBR. The cost reductions for a 1 km section of the pavement were expected to be 12.5%.
PubMed: 38891532
DOI: 10.3390/polym16111586 -
Italian Journal of Food Safety May 2024The aim of this work is the description and characterization of a severe microsporidian infection in a batch of salted and dried cod. Particularly, the case involves a...
The aim of this work is the description and characterization of a severe microsporidian infection in a batch of salted and dried cod. Particularly, the case involves a batch of approximately 800 kg obtained from (Food and Agriculture Organization Zone 61 - Northwest Pacific Ocean), which, after rehydration and sectioning operations, underwent routine company checks before packaging. In about 20% of the samples, the presence of whitish nodules with a diameter ranging from 1 to 2 mm was observed on the surface of the fillets and in cross-section. The lesions ranged from a few units to 10 per cm. Some samples were subjected to fresh microscopic observation with the stereomicroscope, confirming the nodular nature of the lesions, which were often confluent, alternating with empty spaces, giving the tissue a honeycombing aspect. The histological examination at low magnification allowed us to observe the heavy vacuolization of nodular lesions irregularly surrounded by a spongy-like wall. The observation at higher magnification of other sections allowed us to identify intra-myofibrillar cists containing presumptive microsporidian elements. The tissue damage derived from the technological processes and gravity of lesions did not allow a morphological characterization of presumptive protozoans. The molecular examination of the nodular lesions and the analysis of the sequence of an 897 bp fragment of the small subunit 16S rRNA revealed 100% identity with (GenBank accession number MT928885-89) first isolated from the skeletal muscles of specimens from the Sea of Okhotsk. This finding confirms the importance of selecting suppliers and raw materials in the seafood industry, as well as the usefulness of an effective traceability system.
PubMed: 38887589
DOI: 10.4081/ijfs.2024.12333 -
MethodsX Jun 2024Next-generation sequencing requires intact and high-quality DNA. However, typical liquid-nitrogen DNA extraction methods are expensive and not practical for field sample...
Next-generation sequencing requires intact and high-quality DNA. However, typical liquid-nitrogen DNA extraction methods are expensive and not practical for field sample collections. Hence, we present a cost-effective method for DNA extraction from silica-dried leaf samples, eliminating the need for liquid nitrogen. Two protocols were evaluated to determine the effectiveness of grinding dried plant samples without liquid nitrogen in comparison to the standard protocol for tissue homogenization and cell lysis. Protocol 1 involved grinding fresh leaf samples with liquid nitrogen, while Protocol 2 entailed incubating dried plant samples at-20 °C for 1 h before grinding in the absence of liquid nitrogen. Both protocols produced comparable DNA yields with an average A260/A280 ratio of 1.78±0.02, suitable for short- and long-read sequencing. Using Protocol 2, we successfully assembled ten plastomes. It also demonstrated versatility as comparable DNA quality was obtained from dried mollusks and actinomycetes, resulting in the successful assembly of two complete mitochondrial genomes. The protocol is advantageous for research workflows involving the collection of samples in the field as a long-term source of genetic material.•Drying: Fresh samples were silica-dried at silica-to-sample ratio of 2:1.•Pre-lysis: Dried samples were frozen at -20 °C for 1 hour before grinding.•Frozen samples were subjected to tissue homogenization followed by the standard CTAB DNA extraction.
PubMed: 38883586
DOI: 10.1016/j.mex.2024.102758 -
Journal of Pharmacy & Bioallied Sciences Apr 2024Complex anatomy of the root canal system results in incomplete debridement with mechanical instrumentation, leaving some areas or root canal walls untouched. There comes...
INTRODUCTION
Complex anatomy of the root canal system results in incomplete debridement with mechanical instrumentation, leaving some areas or root canal walls untouched. There comes the significance of endodontic irrigants with residual antibacterial substantivity which prolongs the post-antibiotic effect, thereby improving the success and predictability of endodontic treatment.
AIM
To comparatively evaluate the residual antibacterial substantivity of 2% chlorhexidine, Biopure MTAD and 2% chitosan against at intervals of 1, 14 and 28 days.
MATERIALS AND METHODS
Seventy-five therapeutically extracted permanent single rooted mandibular premolars teeth were selected. Dentin blocks of 4 mm thickness were prepared and enlarged to 1.6 mm. The autoclaved blocks were inoculated with 24-hour colonies of pure cultures of for 14 days. After the contamination period, canals of each dentin block were irrigated with 5 ml of sterile saline and dried with sterile paper points. A total of 75 dentin blocks were randomly divided into five groups as follows: Group A (21 specimens): 2% chlorhexidine, Group B (21 specimens): Biopure MTAD, Group C (21 specimens): 2% chitosan, Group D (6 specimens): positive control (infected dentin tubes) and Group E (six specimens): negative control (sterile dentin tubes). Then, the lumens of dentin blocks were irrigated with the respective irrigants for 10 mins and were dried using sterile paper points. The specimens were then incubated at 37°C for 28 days to maintain humidity. At experimental intervals of 1, 14 and 28 days, dentin shavings were removed from the canals of respective groups by circumferential filing with sterile no. 35 Hedstrom files. The powdered dentin samples obtained with each dentin block were observed for colony forming units (CFUs) using a Digital Colony counter and were expressed as CFUs/mL.
RESULT
All the irrigants in the study showed a significant decrease in CFUs from day 1 to day 28 indicating that they have residual antibacterial substantivity against . Group B (Biopure MTAD) showed significantly least mean CFUs compared to Group A (2% CHX) and Group C (2% chitosan) against at B1(day 1), B2(day 14) and B3(day 28). Group A (2% CHX) showed significantly higher mean CFUs than Group C (2% chitosan) at A1(day 1). Group C (2% chitosan) showed significantly higher mean CFUs compared to Group A (2% CHX) at C2(day 14) and C3 (day 28).
CONCLUSION
MTAD showed statistically higher residual antibacterial substantivity against at experimental periods of 1, 14 and 28 days. The residual antibacterial effect of 2% chitosan was better compared to 2% CHX at day 1. The residual antimicrobial substantivity of 2% CHX was higher compared to 2% chitosan at intervals of 14 and 28 days.
PubMed: 38882860
DOI: 10.4103/jpbs.jpbs_693_23 -
PLOS Global Public Health 2024Testing for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) using dried blood spot (DBS) specimens has been an integral part of bio-behavioural...
Testing for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) using dried blood spot (DBS) specimens has been an integral part of bio-behavioural surveillance in Canada for almost two decades, though less is known regarding the use of DBS in surveillance of other sexually transmitted and blood-borne infections (STBBI). A systematic review was conducted using a peer-reviewed search strategy to assess the current evidence regarding the validity of STBBI testing using DBS specimens. Eligibility criteria included studies reporting use of DBS specimens for STBBI testing with either commercially available or "in-house" tests in populations 15 years of age or older. Studies reporting a measure of validity such as sensitivity, specificity, positive and negative predictive values were eligible for inclusion. Quality of studies and risk of bias were assessed using the QUADAS-2 tool. A total of 7,132 records were identified. Of these, 174 met the criteria for inclusion. Among the studies that reported validity measures, a substantial proportion demonstrated high sensitivity (≥90%) in 62.5% of cases (N = 334/534 sensitivity measurements), and high specificity (≥90%) was observed in 84.9% of instances (N = 383/451 specificity measurements). However, the quality of the studies varied greatly. Our findings support the validity of the use of DBS specimens in STBBI testing where sufficient evidence was available, but validity is highly dependent on thorough method development and validation.
PubMed: 38875246
DOI: 10.1371/journal.pgph.0003320 -
IMA Fungus Jun 2024Molecular studies of fungi within the order Laboulbeniales (Ascomycota, Pezizomycotina) have been hampered for years because of their minute size, inability to grow in...
Molecular studies of fungi within the order Laboulbeniales (Ascomycota, Pezizomycotina) have been hampered for years because of their minute size, inability to grow in axenic culture, and lack of reliable and cost-efficient DNA extraction protocols. In particular, the genus Laboulbenia is notorious for low success with DNA extraction and polymerase chain reaction (PCR) amplification. This is attributed to the presence of melanin, a molecule known to inhibit PCR, in the cells. We evaluated the efficacy of a standard single cell-based DNA extraction protocol by halving the recommended amount of reagents to reduce the cost per extraction and adding bovine serum albumin (BSA) during the multiple displacement amplification step to reverse the effect of melanin. A total of 196 extractions were made, 111 of which were successful. We found that halving the reagents used in the single cell-based extraction kit did not significantly affect the probability of successful DNA extraction. Using the halved protocol reduces cost and resource consumption. Moreover, there was no significant difference in the probability of successfully extracting DNA based on whether BSA was added or not, suggesting that the amount of melanin present in cells of the thallus has no major inhibitory effect on PCR. We generated 277 sequences from five loci, but amplification of the internal transcribed spacer region, the mitochondrial small subunit rDNA, and protein-coding genes remains challenging. The probability of successfully extracting DNA from Laboulbeniales was also impacted by specimen storage methods, with material preserved in > 95% ethanol yielding higher success rates compared to material stored in 70% ethanol and dried material. We emphasize the importance of proper preservation of material and propose the design of Laboulbeniales-specific primers to overcome the problems of primer mismatches and contaminants. Our new insights apply not only to the genus Laboulbenia; Laboulbeniales generally are understudied, and the vast majority of species remain unsequenced. New and approachable molecular developments will benefit the study of Laboulbeniales, helping to elucidate the true diversity and evolutionary relationships of these peculiar microfungi.
PubMed: 38863065
DOI: 10.1186/s43008-024-00146-9 -
Nature Communications Jun 2024The SpaceX Inspiration4 mission provided a unique opportunity to study the impact of spaceflight on the human body. Biospecimen samples were collected from four crew...
The SpaceX Inspiration4 mission provided a unique opportunity to study the impact of spaceflight on the human body. Biospecimen samples were collected from four crew members longitudinally before (Launch: L-92, L-44, L-3 days), during (Flight Day: FD1, FD2, FD3), and after (Return: R + 1, R + 45, R + 82, R + 194 days) spaceflight, spanning a total of 289 days across 2021-2022. The collection process included venous whole blood, capillary dried blood spot cards, saliva, urine, stool, body swabs, capsule swabs, SpaceX Dragon capsule HEPA filter, and skin biopsies. Venous whole blood was further processed to obtain aliquots of serum, plasma, extracellular vesicles and particles, and peripheral blood mononuclear cells. In total, 2,911 sample aliquots were shipped to our central lab at Weill Cornell Medicine for downstream assays and biobanking. This paper provides an overview of the extensive biospecimen collection and highlights their processing procedures and long-term biobanking techniques, facilitating future molecular tests and evaluations.As such, this study details a robust framework for obtaining and preserving high-quality human, microbial, and environmental samples for aerospace medicine in the Space Omics and Medical Atlas (SOMA) initiative, which can aid future human spaceflight and space biology experiments.
Topics: Humans; Space Flight; Biological Specimen Banks; Specimen Handling; Astronauts
PubMed: 38862509
DOI: 10.1038/s41467-024-48806-z -
F1000Research 2023The sternum exhibits unique anatomical variations with major clinical and forensic implications. This study is devoted to providing baseline epidemiological information... (Observational Study)
Observational Study
The sternum exhibits unique anatomical variations with major clinical and forensic implications. This study is devoted to providing baseline epidemiological information about the sternal foramen and variant xiphoid morphology in Ethiopia. Two extremely interesting and unusual variations of the sternal foramen are also discussed. This observational study was carried out using dried adult human sternum obtained from skeletal remains samples brought for medicolegal examination over a period of 4 years. A total of 94 dried adult human sternums (66 males (70.2%) and 28 females (29.8%)) were obtained with an age range of 21 to 57 years and a mean age at death of 38.383 ± 11.3480 years. Dried human sternum specimens were morphologically examined, and morphometric parameters were recorded and photographed. A sternal foramen was found in 18 specimens (19.1%); 17 were male and one was female. A single sternal foramen was observed in 83.3% (n=15/18) of the sternal bodies and 11.1% (n=2/18) of the xiphoid processes (both males). In addition, a double sternal foramen was observed in a single male specimen on the mesosternum and xiphoid process. The most common sternal foramen site was at the fifth costochondral junction level. The xiphoid process was present in 77 samples and ended as a single process in 83.1% (n=64/77) of samples. In 15.6% (n=12/77) of the samples, the xiphoid process was bifurcated and trifurcated in a single male (1.3%) specimen. The sternal foramen and variation in xiphoid morphology are common anatomical variations in Ethiopia. The findings of the current study highlight the necessity of strict precautionary measures during sternal procedures in this study population. In addition, such incidental findings during radiologic and autopsy procedures should be properly evaluated to avoid misdiagnosis and misinterpretation of such findings as traumatic or pathologic conditions.
Topics: Humans; Sternum; Male; Female; Ethiopia; Adult; Middle Aged; Young Adult; Anatomic Variation; Xiphoid Bone
PubMed: 38845617
DOI: 10.12688/f1000research.133151.1 -
Plant Disease May 2024Since the emergence of Ug99 wheat stem rust in Uganda in 1998 (Pretorius et al. 2000), the threat of movement into South Asia has been a concern due to long-distance...
Since the emergence of Ug99 wheat stem rust in Uganda in 1998 (Pretorius et al. 2000), the threat of movement into South Asia has been a concern due to long-distance dispersal capacity of airborne spores (Brown and Hovmøller 2002; Singh et al. 2008; Meyer et al. 2017). Increased preparedness by comprehensive rust surveillance efforts and development and deployment of resistant cultivars in advance of an incursion into South Asia has been one of the success stories of the Borlaug Global Rust Initiative (Sharma et al. 2013). In November 2023, an off-season rust survey was conducted in Marpha, Gandaki and Bagmati provinces in Nepal. Rust was only observed at two sites, Dangdunge of Dolakha district and Mude of Sindhupalchok district, where spring wheat was grown as fodder crop outside the main cropping season. Rust infected wheat leaves (10-15 leaves per site) were air dried and sealed in envelopes that were shipped under permit to the Global Rust Reference Center, Denmark. Bulk samples of stem rust, Puccinia graminis f.sp. tritici (Pgt), were recovered from both envelopes, and single pustule isolates were raised and multiplied on Morocco and McNair. Meanwhile, specimens of dry leaves were subjected to SSR genotyping according to standard procedures (Patpour et al. 2022). One distinct multi-locus Pgt genotype was observed, identical to and representing 99% of Ug99 isolates within Clade I collected in East Africa between 2012-2022. A Pgt single pustule isolate from each of the sampling sites were inoculated onto 20 internationally agreed stem rust differential lines using standard procedures, and 14 supplementary lines providing additional resolution of pathogen virulence (Patpour et al. 2022). The pathotyping was repeated in two independent experiments, which resulted in the infection type pattern of Pgt race TTKTT (Supplementary Table 1). Additional independent SSR genotype assays of recovered isolates confirmed the prevalent genotype of Clade I (Patpour et al. 2022; Szabo et al. 2022). This first detection of Ug99 race TTKTT in South Asia emphasizes the need for continued coordinated international surveillance efforts and utilization of diverse sources of resistance to control stem rust in wheat. New surveillance efforts in Nepal during February-March 2024 did not reveal additional cases of wheat stem rust. However, more detailed and sustained rust surveillance efforts, assessment of the vulnerability of current wheat crops to Ug99 and other races of stem-, stripe/yellow- and leaf rust, as well as intensified breeding for rust resistance throughout the region is strongly recommended to meet current and future plant health risks.
PubMed: 38812370
DOI: 10.1094/PDIS-03-24-0644-PDN -
Bioengineering (Basel, Switzerland) May 2024The application of calcium coacervates (CCs) may hold promise for dental hard tissue remineralization. The aim of this study was to evaluate the effect of the...
The application of calcium coacervates (CCs) may hold promise for dental hard tissue remineralization. The aim of this study was to evaluate the effect of the infiltration of artificial enamel lesions with a CC and its single components including polyacrylic acid (PAA) compared to that of the self-assembling peptide P-4 in a pH-cycling (pHC) model. Enamel specimens were prepared from bovine incisors, partly varnished, and stored in demineralizing solution (DS; pH 4.95; 17 d) to create two enamel lesions per sample. The specimens were randomly allocated to six groups (n = 15). While one lesion per specimen served as the no-treatment control (NTC), another lesion (treatment, T) was etched (HPO, 5 s), air-dried and subsequently infiltrated for 10 min with either a CC (10 mg/mL PAA, 50 mM CaCl (Ca) and 1 M KHPO (PO)) (groups CC and CC + DS) or its components PAA, Ca or PO. As a commercial control, the self-assembling peptide P-4 (Curodont Repair, Credentis, Switzerland) was tested. The specimens were cut perpendicularly to the lesions, with half serving as the baseline (BL) while the other half was exposed to either a demineralization solution for 20 d (pH 4.95; group CC + DS) or pHC for 28 d (pH 4.95, 3 h; pH 7, 21 h; all five of the other groups). The difference in integrated mineral loss between the lesions at BL and after the DS or pHC, respectively, was analyzed using transversal microradiography (ΔΔZ = ΔZ - ΔZ). Compared to the NTC, the mineral gain in the T group was significantly higher in the CC + DS, CC and PAA ( < 0.05, Wilcoxon). In all of the other groups, no significant differences between treated and untreated lesions were detected ( > 0.05). Infiltration with the CC and PAA resulted in a consistent mineral gain throughout the lesion body. The CC as well as its component PAA alone promoted the remineralization of artificial caries lesions in the tested pHC model. Infiltration with PAA further resulted in mineral gain in deeper areas of the lesion body.
PubMed: 38790332
DOI: 10.3390/bioengineering11050465