Egg white based biological microlasers Nguyen, Toan Van; Mai, Hanh Hong; Nguyen, Thuong Van ...
Journal of physics. D, Applied physics,
10/2020, Letnik:
53, Številka:
44
Journal Article
Recenzirano
Biolasers made of biological materials hold great potential for implantable biosensing and cell-tracking. However, the current bio-extracted materials used for biolasers generally require a ...complicated synthesis process and therefore suffer from high cost. In this work, we demonstrate that low-cost natural egg white is an excellent biomaterial for a laser cavity. Using a simple dehydration method, dye-doped goose egg white microspheres are obtained with various sizes from 20 to 160 µm in diameter. These microspheres can act as excellent laser sources under optical excitation with lasing threshold of ∼26 µJ mm−2 and quality (Q) factor up to 3 × 103. The lasing mechanism is studied and ascribed to the whispering gallery mode. Size-dependence of the lasing spectrum and Q factor are also investigated. Owing to the ease of fabrication, the cost-effectiveness, goose egg white based microlasers are promising for biosensing and bioimaging applications.
Consider the indentation of an anisotropic piezoelectric half-plane by multiple rigid punches. By using the Stroh's formalism for anisotropic piezoelasticity and the analytical continuation method ...for complex function's manipulation, a unified full-field solution is obtained for four different contact conditions including adhesive contact with conducting punches, adhesive contact with insulating punches, frictional contact with conducting punches, and frictional contact with insulating punches. To demonstrate the generality and applicability of the unified general solution, the closed-form solutions for some benchmark problems such as indentation by one flat-ended punch, one parabolic punch, or multiple flat-ended punches are then derived. With the numerical results evaluated by the closed-form solutions, the effects of anisotropy, poling direction, frictional coefficient, contact condition, applied loads, and punch interaction are also studied and discussed.
•A brand-new BEM for 2D anisotropic solid indented by multiple rigid punches.•Elastic/viscoelastic and frictional static/sliding contact are all considered.•Analytical solutions are derived for ...certain cases with viscoelastic solids.•Both incomplete and complete indentation are studied for elastic solids.•No meshes are required on the boundaries of rigid punches and holes/cracks.
A two-dimensional anisotropic elastic or viscoelastic solid indented by multiple rigid punches is considered. By taking the rigid body translation and rotation of each punch as the additional variables to the usual contact boundary element method (BEM), we propose a brand-new BEM in which the additional equations come from the force/moment equilibrium of each punch. In this newly developed BEM, the selected fundamental solutions are valid for the general anisotropic elastic/viscoelastic solids with or without holes/cracks. Under this consideration, no meshes are required on the boundaries of rigid punches and holes/cracks, which makes it much more accurate and efficient than the conventional contact BEM. This method is valid for the frictionless or frictional contact surface, and the punches can be in equilibrium status or in quasistatic sliding condition. If the solids are anisotropic elastic, it is applicable for both incomplete and complete indentation. Since the extension from elastic to viscoelastic is based upon the elastic-viscoelastic correspondence principle that requires all the boundaries be time-independent, our method is valid only for complete indentation if the indented solid is viscoelastic. In addition to this new BEM, in order to verify our results for the cases with viscoelastic solids, by proper use of Laplace transform and its inversion, new analytical solutions for the indentation by a flat-ended/parabolic punch are also presented for the half-plane made by anisotropic viscoelastic materials.
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Summary Background Improved understanding of pathogens that cause sepsis would aid management and antimicrobial selection. In this study, we aimed to identify the causative pathogens of sepsis in ...southeast Asia. Methods In this multinational multicentre cross-sectional study of community-acquired sepsis and severe sepsis, we prospectively recruited children (age ≥30 days and <18 years) and adults (age ≥18 years) at 13 public hospitals in Indonesia (n=3), Thailand (n=4), and Vietnam (n=6). Hospitalised patients with suspected or documented community-acquired infection, with at least three diagnostic criteria for sepsis according to the Surviving Sepsis Campaign 2012, and within 24 h of admission were enrolled. Blood from every patient, and nasopharyngeal swab, urine, stool, and cerebrospinal fluid, if indicated, were collected for reference diagnostic tests to identify causative pathogens. We report causative pathogens of sepsis and 28-day mortality. We also estimate mortality associated with enrolment with severe sepsis. This study was registered with ClinicalTrials.gov , number NCT02157259. Findings From Dec 16, 2013, to Dec 14, 2015, 4736 patients were screened and 1578 patients (763 children and 815 adults) were enrolled. Dengue viruses (n=122 8%), Leptospira spp (n=95 6%), rickettsial pathogens (n=96 6%), Escherichia coli (n=76 5%), and influenza viruses (n=65 4%) were commonly identified in both age groups; whereas Plasmodium spp (n=12 1%) and Salmonella enterica serovar Typhi (n=3 0·2%) were rarely observed. Emerging pathogens identified included hantaviruses (n=28 2%), non-typhoidal Salmonella spp (n=21 1%), Streptococcus suis (n=18 1%), Acinetobacter spp (n=12 1%), and Burkholderia pseudomallei (n=5 <1%). 28-day mortality occurred in 14 (2%) of 731 children with known statuses and 108 (13%) of 804 adults. Severe sepsis was identified on enrolment in 194 (28%) of 731 children and 546 (68%) of 804 adults, and was associated with increased mortality (adjusted odds ratio 5·3, 95% CI 2·7–10·4; p<0·001). Interpretation Sepsis in southeast Asia is caused by a wide range of known and emerging pathogens, and is associated with substantial mortality. Funding National Cancer Institute, National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA, and Wellcome Trust, UK.
Community-acquired (CA) sepsis is a major public health problem worldwide, yet the etiology remains unknown for >50% of the patients. Here we applied metagenomic next-generation sequencing (mNGS) to ...characterize the human virome in 492 clinical samples (384 sera, 92 pooled nasal and throat swabs, 10 stools, and 6 cerebrospinal fluid samples) from 386 patients (213 adults and 173 children) presenting with CA sepsis who were recruited from 6 hospitals across Vietnam between 2013 and 2015. Specific monoplex PCRs were used subsequently to confirm the presence of viral sequences detected by mNGS. We found sequences related to 47 viral species belonging to 21 families in 358 of 386 (93%) patients, including viruses known to cause human infections. After PCR confirmation, human viruses were found in 52 of 386 patients (13.4%); picornavirus (enteroviruses
= 14, rhinovirus
= 5, and parechovirus
= 2), hepatitis B virus (
= 10), cytomegalovirus (
= 9), Epstein-Barr virus (
= 5), and rotavirus A (
= 3) were the most common viruses detected. Recently discovered viruses were also found (gemycircularvirus
= 5 and WU polyomavirus, Saffold virus, salivirus, cyclovirus-VN, and human pegivirus 2 HPgV2
, 1 each), adding to the growing literature about the geographic distribution of these novel viruses. Notably, sequences related to numerous viruses not previously reported in human tissues were also detected. To summarize, we identified 21 viral species known to be infectious to humans in 52 of 386 (13.4%) patients presenting with CA sepsis of unknown cause. The study, however, cannot directly impute sepsis causation to the viruses identified. The results highlight the fact that it remains a challenge to establish the causative agents in CA sepsis patients, especially in tropical settings such as Vietnam.
Comprehensive profiling of actionable mutations in non-small cell lung cancer (NSCLC) is vital to guide targeted therapy, thereby improving the survival rate of patients. Despite the high incidence ...and mortality rate of NSCLC in Vietnam, the actionable mutation profiles of Vietnamese patients have not been thoroughly examined. Here, we employed massively parallel sequencing to identify alterations in major driver genes (EGFR, KRAS, NRAS, BRAF, ALK and ROS1) in 350 Vietnamese NSCLC patients. We showed that the Vietnamese NSCLC patients exhibited mutations most frequently in EGFR (35.4%) and KRAS (22.6%), followed by ALK (6.6%), ROS1 (3.1%), BRAF (2.3%) and NRAS (0.6%). Interestingly, the cohort of Vietnamese patients with advanced adenocarcinoma had higher prevalence of EGFR mutations than the Caucasian MSK-IMPACT cohort. Compared to the East Asian cohort, it had lower EGFR but higher KRAS mutation prevalence. We found that KRAS mutations were more commonly detected in male patients while EGFR mutations was more frequently found in female. Moreover, younger patients (<61 years) had higher genetic rearrangements in ALK or ROS1. In conclusions, our study revealed mutation profiles of 6 driver genes in the largest cohort of NSCLC patients in Vietnam to date, highlighting significant differences in mutation prevalence to other cohorts.
Cordycepin, a major compound of Cordyceps sp., has been shown to have anticancer potential. However, its low solubility in water is a hurdle in drug delivery in the human body and for cellular ...uptake. This study focuses on the ability to load cordycepin onto a biodegradable silica nanoparticle as an effective nanocarrier. Biodegradable tetrasulfide-based organosilica nanomaterial with homogeneously spherical particles, average particle size of approximately 50 nm, and pore size of 3.56 nm were successfully synthesized. The nanomaterial could efficiently load cordycepin with a loading capacity up to 755.02 mg g−1. The release profile of cordycepin-loaded nanoparticles at pH 5.5 showed a burst release within the first 1 h and a gradually slow rate thereafter. Moreover, the results of in vitro toxicity of the drug-loaded material against two malignant cancer cell lines including gastric (AGS) and lung (A549) indicated the potential of the nanosystem for drug delivery in cancer therapy.
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➢Biodegradable nanoparticles (NPs) were successfully prepared by sol-gel condensation of ethane- and tetrasulfide-based linkers.➢The synthesized NPs possess a high specific surface area and a large pore size (3.56 nm) with small particle size approximately 50 nm.➢NPs could completely degrade under redox condition after 7 days➢The material showed high loading capacity of cordycepin, up to 755.02 mg g−1.➢In vitro toxicity studies exhibited that cordycepin-loaded NPs could efficiently kill cancer cells (AGS and A549), but not harm the normal cells at moderate concentrations.
Severe dengue with severe plasma leakage (SD-SPL) is the most frequent of dengue severe form. Plasma biomarkers for early predictive diagnosis of SD-SPL are required in the primary clinics for the ...prevention of dengue death.
Among 63 confirmed dengue pediatric patients recruited, hospital based longitudinal study detected six SD-SPL and ten dengue with warning sign (DWS). To identify the specific proteins increased or decreased in the SD-SPL plasma obtained 6-48 hours before the shock compared with the DWS, the isobaric tags for relative and absolute quantification (iTRAQ) technology was performed using four patients each group. Validation was undertaken in 6 SD-SPL and 10 DWS patients.
Nineteen plasma proteins exhibited significantly different relative concentrations (p<0.05), with five over-expressed and fourteen under-expressed in SD-SPL compared with DWS. The individual protein was classified to either blood coagulation, vascular regulation, cellular transport-related processes or immune response. The immunoblot quantification showed angiotensinogen and antithrombin III significantly increased in SD-SPL whole plasma of early stage compared with DWS subjects. Even using this small number of samples, antithrombin III predicted SD-SPL before shock occurrence with accuracy.
Proteins identified here may serve as candidate predictive markers to diagnose SD-SPL for timely clinical management. Since the number of subjects are small, so further studies are needed to confirm all these biomarkers.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This work is to produce multi‐functional active film from polyvinyl (alcohol)/chitosan (PCs) supplemented with Sonneratia ovata leaf extract (SOE) and Piper betel L. oil (PBLO). Our finding showed ...yellowish SOE‐added PCs film with the compact structure possessing lower swelling degree (SD) (22.48%) and higher mechanical strength (5.05 MPa) as compared to the neat PCs (35.43% and 3.18 MPa, respectively). While the co‐supplementation with PBLO at different ratios significantly increased SD between 50.97% and 104.08% due to the more open structure. UV‐barrier, antimicrobial, and antioxidant properties of PCs film were significantly revitalized with co‐supplementation of SOE and PBLO. The PCs/SOE1/PBLO0.5 film presented better force resistance (5.51 MPa) and flexibility (87.12%) than other film formulations with balanced antibacterial and antioxidant properties and hence, it was further applied for preserving fresh‐cut beef for 14 days at 4°C. Changes in visual appearance, drip loss, and pH of fresh‐cut beef during storage period indicated better protective efficacy of PCs/SOE1/PBLO0.5 film as compared to polyethylene (PE), PCs, and SOE‐added PCs materials, suggesting its promisingly potential for food packaging application.
Bioactive and functional biodegradable films are produced from polyvinyl (alcohol)/chitosan incorporated with Sonneratia ovata leaf extract and Piper betel L. leaves essential oil for the purpose of enhancing mechanical behavior, UV‐barrier, antioxidant, and antimicrobial properties of resulting films as well as prolonging the shelf life of fresh‐cut beef.
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