Aims
Presently, the effective antimicrobial agents have been limited by the emergence of microbial strains with multidrug resistance and biofilm formation potential. In the present study, we report ...remarkable antimicrobial activity of silver nanoparticles (AgNPs) synthesized from Streptomyces calidiresistens IF11 and IF17 strains, including inhibition of biofilm formation and synergistic effect of AgNPs and antibiotics against selected bacteria and yeasts. Cytotoxic effect of AgNPs on mammalian cell lines was also evaluated.
Methods and Results
Analysis of biosynthesized AgNPs by Fourier Transform Infrared Spectroscopy and transmission electron microscopy revealed their spherical shape, small size in the range of 5–50 and 5–20 nm, respectively, as well as the presence of capping agents. Study of antimicrobial activity of AgNPs against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans and Malassezia furfur evaluated by minimum inhibitory concentration (MIC) and minimum biocidal concentration (MBC) assays revealed that MICs of AgNPs from IF11 and IF17 strains against bacteria and yeasts were found to be in the range of 16–128 and 8–256 μg ml−1, while MBCs were in the range of 48–192 and 32–256 μg ml−1 respectively. AgNPs inhibited biofilm formation of microbial strains, which was tested by using crystal violet stain. The highest synergistic effect determined by fractional inhibitory index of AgNPs with antibiotic (kanamycin or tetracycline) was found against Staph. aureus; while in case of yeasts, M. furfur showed highest sensitivity to AgNPs‐ketoconazole combination (FIC = 0·12). The cytotoxic activity of AgNPs towards HeLa and 3T3 cell lines was studied by MTT assay. The IC50 of AgNPs estimated against mouse fibroblasts was found to be 8·3 and 28·3 μg ml−1 and, against HeLa cell line, 28·5 and 53·8 μg ml−1 respectively.
Conclusions
It can be concluded that AgNPs synthesized from S. calidiresistens IF11 and IF17 strains have potential as an effective antimicrobial and cytotoxic agent, especially when used in combination with antibiotics/antifungal agents.
Significance and Impact of the Study
This study indicates potential application of biogenic silver nanoparticles as an antimicrobial agent in nanomedicine.
This study was carried out to look for diagnostic and prognostic role of neutrophil gelatinase-associated lipocalin (NGAL) in early diabetic nephropathy (DN) in type 2 diabetes individuals. NGAL was ...measured in both urinary and serum sample of 144 type 2 diabetes individuals stratified into three categories based on urinary albumin-creatinine ratio and 54 control populations with estimated glomerular filtration rate >60 mL/min/1.73 m2 and serum creatinine <1.2 mg/dl. The serum NGAL (sNGAL), urine NGAL (uNGAL), and uNGAL/urine creatinine were significantly higher in diabetic individuals than in the control populations with significant difference in between the groups (P < 0.05). Difference of above values between control value and normoalbuminuria was also statistically significant (P < 0.05). Again, sNGAL and uNGAL correlate positively with albuminuria (P < 0.05). Tubular injury may precede glomerular injury in diabetic individuals, and NGAL can be used as a biomarker to diagnose DN even earlier to incipient nephropathy. Both sNGAL and uNGAL can predict albuminuria and be used as a noninvasive tool for diagnosis, staging, and progression of DN.
SARS-CoV-2 mRNA booster vaccines provide protection from severe disease, eliciting strong immunity that is further boosted by previous infection. However, it is unclear whether these immune responses ...are affected by the interval between infection and vaccination. Over a 2-month period, we evaluated antibody and B cell responses to a third-dose mRNA vaccine in 66 individuals with different infection histories. Uninfected and post-boost but not previously infected individuals mounted robust ancestral and variant spike-binding and neutralizing antibodies and memory B cells. Spike-specific B cell responses from recent infection (<180 days) were elevated at pre-boost but comparatively less so at 60 days post-boost compared with uninfected individuals, and these differences were linked to baseline frequencies of CD27lo B cells. Day 60 to baseline ratio of BCR signaling measured by phosphorylation of Syk was inversely correlated to days between infection and vaccination. Thus, B cell responses to booster vaccines are impeded by recent infection.
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•Pre-boost SARS-CoV-2 antibodies and B cells are elevated by prior infection•Post-boost SARS-CoV-2 antibodies and B cells are muted by prior infection•Interval from infection to vaccination inversely correlates with booster response•Pre-boost RBD-specific CD21+CD27lo B cells are associated with booster response
For COVID-19 mRNA vaccines, immunization with a booster dose elicits robust antibody and B cell responses that are further increased if a breakthrough infection occurs after vaccination. In contrast, when infection occurs prior to booster vaccination, antibody and B cell responses are muted closer to the infection time and achieve better levels as the time interval between infection and vaccination increases.
Despite unparalleled research efforts to find a cure, there is a growing sentiment in the field that complete viral eradication is unlikely with existing therapies. ...an approach involving ...immune-mediated virologic control without ART represents a realistic goal, even if the HIV reservoir persists (1). Blood products were obtained in accordance with a protocol approved by the Institutional Review Board of the National Institute of Allergy and Infectious Diseases of the NIH. IPD burdens were relatively high in EC-4 and EC-6 (75 and 105 copies/106 cells, respectively). ...we conducted longitudinal measurements of ivRNA and IPD (EC-4) and near full-length sequencing of HIV DNA from a sorted CD4+ T subset (EC-6).
Emerging evidence suggests that injury to the anterior cruciate ligament (ACL) typically initiates biological changes that contribute to the development of osteoarthritis (OA). The molecular ...biomarkers or mediators of these biological events remain unknown. The goal of this exploratory study was to identify novel synovial fluid biomarkers associated with early biological changes following ACL injury distinct from findings in end-stage OA.
Synovial fluid was aspirated from patients with acute (≤30 days) and subacute (31–90 days) ACL tears and from patients with advanced OA and probed via tandem mass spectrometry for biomarkers to distinguish OA from ACL injury. Periostin (POSTN) was identified as a potential candidate. Further analyses of POSTN were performed in synovial fluid, OA cartilage, torn ACL remnants, and cultured cells and media by Western blot, PCR, immunostaining and ELISA.
Synovial fluid analysis revealed that POSTN exhibited higher expression in subacute ACL injury than OA. POSTN expression was relatively low in cartilage/chondrocytes suggesting it is also produced by other intra-articular tissues. Conversely, high and time-dependent expression of POSTN in ACL tear remnants and isolated cells was consistent with the synovial fluid results.
Elevated POSTN may provide a synovial fluid biomarker of subacute ACL injury setting separate from OA. Increased expression of POSTN in ACL suggests that the injured ACL may play a pivotal role in POSTN production, which is sensitive to time from injury. Previous studies have shown potential catabolic effects of POSTN, raising the possibility that POSTN contributes to the initiation of joint degeneration and may offer a window of opportunity to intervene in the early stages of post-traumatic OA.
•Issues of paid and unpaid social reproductive work need to be aligned to sustain decent work agenda.•Growth indicators for SDG 8 targets neglect the value and costs of social reproduction.•Decent ...work agenda is unsustainable if it neglects persistent gender inequality globally (SDG 5).
SDG 8 calls for promoting ‘sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all’. Even as it highlights the importance of labour rights for all, it also makes visible some significant tensions. We note, for example, that despite many critiques of narrow economic measures of growth, the focus here remains on GDP and per capita growth. This is problematic, we argue, because the GDP productive boundary excludes much of social reproductive work. This puts SDG8 in tension with SDG 5 which calls for the recognition of the value of unpaid care and domestic work. There has been a significant increase in the rate of working women in the formal and informal sector. However, there has not been a subsequent gender shift in the doing of social reproductive work. In this paper we argue SDG 8’s focus on decent work and economic growth is inadequate; that productive employment and decent work for all men and women by 2030 needs to take into account the value and costs of social reproduction. We trace key historical debates on work to argue that both gender and labour rights have to underpin SDG 8 if its promise of inclusive, sustainable and decent work is to be realized.
Lanthanides are among the most acceptable activator ions for cool white light emission; however, solid state lighting for some applications requires a warm white light. Herein, the present work ...probes a new approach for color temperature tuning in such systems to get a warm white light. The idea is that the additional use of red spectral components in cool white light, to a certain extent, may lead to a perfect warm white light, which can be achieved by making use of the surface oxygen defects mediated red emission from ZnO. To realize this noble concept, white light was initially produced in Y(1.993)Dy(0.001)Tm(0.006)O3 and then further ZnO was added. The study includes detailed structural and optical (steady state and time domain) characterization, chromaticity coordinates (CIE) calculation and correlated color temperature (CCT) analysis. The results show that, initially, at low ZnO concentration, Zn(2+) ions prefer to go into the interstitial sites, due to the mismatch of ionic radius between Y(3+) (0.90 Å) and Zn(2+) (0.75 Å). However, beyond a 10 mol% concentration of ZnO, the solubility limit of Zn(2+) ions in the Y2O3 matrix is reached, which results in the development of a Y2O3-ZnO composite. The presence of the ZnO phase gives rise to defect level induced red emission, which tunes the color temperature from 6072 K to 3898 K, which is reasonably good warm white light for solid state lighting applications. This idea can also be generalized in other similar hosts for developing potential warm white light sources.
A novel synthesis of thiazolo2,3-bquinazolines
(
-
), pyrido2',3':4,5thiazolo2,3-bquinazolines {
(
-
),
(
-
), and
(
-
)}, pyrano2',3':4,5thiazolo2,3-bquinazolines
(
-
), and ...benzo4,5thiazolo2,3-bquinazoloine
(
-
) derivatives starting from 2-(Bis-methylsulfanyl-methylene)-5,5-dimethyl-cyclohexane-1,3-dione
as efficient α,α dioxoketen dithioacetal is reported and the synthetic approaches of these types of compounds will provide an innovative molecular framework to the designing of new active heterocyclic compounds. In our study, we also present optimization of the synthetic method along with a biological evaluation of these newly synthesized compounds as antioxidants and antibacterial agents against the bacterial strains, like
,
and
. Among all the evaluated compounds, it was found that some showed significant antioxidant activity at 10 μg/mL while the others exhibited better antibacterial activity at 100 μg/mL. The results of this study showed that compound
(
) possessed remarkable antibacterial activity, whereas compound
(
) exhibited the highest efficacy as an antioxidant. The structures of the new synthetic compounds were elucidated by elemental analysis, IR,
H-NMR, and
C-NMR.
The sunlight mediated photocatalytic degradation of rhodamine B (RB) dye was studied using hydrothermally prepared ZnO (T = 150°C andP ∼ 20–30 bars). Zinc chloride was used as the starting material ...along with sodium hydroxide as a solvent in the hydrothermal synthesis of ZnO. Different durations were tried to obtain pure ZnO phase, which was later confirmed through powder X-ray diffraction. The photocatalytic behaviour of the prepared ZnO was tested through the degradation of RB. The disappearance of organic molecules follows first-order kinetics. The effect of various parameters such as initial dye concentration, catalyst loading, pH of the medium, temperature of the dye solution, on the photo degradation of RB were investigated. The thermodynamic parameters of the photodegradation of RB, like energy of activation, enthalpy of activation, entropy of activation and free energy of activation revealed the efficiency of the process. An actual textile effluent containing RB as a major constituent along with other dyes and dyeing auxiliaries was treated using hydrothermally synthesized ZnO and the reduction in the chemical oxygen demand (COD) of the treated effluent revealed a complete destruction of the organic molecules along with colour removal.
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