Colorimetric Stimuli-Responsive Hydrogel Polymers for the Detection of Nerve Agent Surrogates

The threat of chemical warfare agents (CWAs) necessitates the development of functional materials that not only quickly detect the presence of CWAs but also actively protect against their toxicity. We have synthesized responsive units that exhibit colorimetric responses upon exposure to CWAs and incorporated them into a versatile detection platform based on copolymers prepared by ring-opening metathesis polymerization (ROMP). The theoretical detection limits for CWA simulants in solution for these polymers are as low as 1 ppm. By incorporating hydrogel-promoting units as pendant chains, we are able to obtain polymers that instantly respond to CWA vapors and are easy to regenerate to the deactivated state by simple treatment with ammonium hydroxide vapor. We further demonstrate a collapse of the polymer gels in response to trifluoroacetic acid (TFA), a strong acid that produces a more fully ionized state as a result of its more caustic nature.United States. Defense Threat Reduction Agency. Chemical and Biological Technologies Department (Grant BA12PHM123

Probiotic characteristics of exopolysaccharides-producing Lactobacillus isolated from some traditional Malaysian fermented foods

This study aims to evaluate the probiotic properties of Lactobacillus strains producing exopolysaccharides (EPS) isolated from different Malaysian fermented foods. Thirty lactobacilli species were isolated, and six of these (TAP1, PIC7, BU11, BU14, TAP16, and TEMP9) were shown to exhibit probiotic characteristics with the potential to produce EPS. The isolates were evaluated for their tolerance to low pH, bile salts, antimicrobial potential, and cell surface properties. The strains were identified using API50CHL and 16S rRNA gene sequences as Lactobacillus belonged to the species fermentum and plantarum. The Lactobacillus strains exhibited high survivability tolerance to low pH and bile salts (above 90%). All strains exhibited auto-aggregation (33.63–59.63%), co-aggregation (24.37–41.9%), and hydrophobicity (16–65.77%) ability. The strains displayed no transferrable antibiotics and antagonistic activity against pathogenic bacteria. Therefore, it indicates that Lactobacillus strains could act as promising probiotic candidates

Role of L- glutamine and crizanlizumab in sickle cell anaemia painful crisis reduction

BackgroundPatients with sickle cell disease, frequently ‎ suffer from intense painful episodes. Till recently hydroxyurea was the only available medical therapy that approved for reduction of painful episodes.AimsTo summarize the available data from randomized controlled trials that aim to evaluate the efficacy of newly approved L-‎glutamine‎ (alters redox state of red blood cells ‎‎[RBCs]) ‎and ‎crizanlizumab (‎(anti-P-selectin)‎)‎ ‎on vaso-occlusive episodes in Sickle cell disease ‎ patients.Methods PubMed, ‎Google Scholar, and EBSCO ‎ databases were ‎‎systematically search for relevant articles. The terms ‎ ‎ ‎ L-glutamine, sickle cell disease, sickle cell ‎anaemia,‎ ‎‎crizanlizumab ‎and vaso-occlusive episodes‎ were used.Results Out of Four-hundred seventy-two records, only three fulfilled the inclusion criteria. Two trials were aimed to evaluate the efficacy of L-glutamine therapy on the frequency of painful crises in sickle cell anaemia patients. Both studies showed that L-glutamine therapy significantly reduce the frequency of VOEs. Only one trial examined the ability of crizanlizumab on VOEs reduction, and showed crizanlizumab successful reduce the occurrence of VOEs.‎ConclusionNewer agent ‎with different mechanism of action, such as ‎L-glutamine, ‎and crizanlizumab may consider if ‎hydroxyurea not effective or not ‎tolerable

Fluorescent Multiblock π-Conjugated Polymer Nanoparticles for In Vivo Tumor Targeting

Highly fluorescent multiblock conjugated polymer nanoparticles with folic acid surface ligands are highly effective for bioimaging and in vivo tumor targeting. The targeted nanoparticles were preferentially localized in tumor cells in vivo, thereby illustrating their potential for diagnostic and therapeutic applications.Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (W911NF-13-D-0001)UNCF-Merck Postdoctoral FellowshipNational Science Foundation (U.S.). Graduate Research Fellowship ProgramMassachusetts Institute of Technology. Dr. Martin Luther King, Jr. Visiting Professors and Scholars Program (Postdoctoral Fellowship)National Cancer Institute (U.S.) (Koch Institute Support (Core) Grant P30-CA14051)National Cancer Institute (U.S.). Center for Cancer Nanotechnology Excellence (Grant 5 U54 CA151884-02

Introducing an Innovative Approach for Managing Proximal Non-Cavitated Carious Lesions in Juvenile Permanent Dentition: Combining Orthodontic Separators and Silver Fluoride Application

Background and Objectives: The aim was to introduce an innovative, easy and cheap clinical approach for the control of multiple proximal non-cavitated lesions via the application of 38% silver fluoride after placement of orthodontic separators in the permanent dentition in high-caries-risk children. Materials and Methods: The case series describes the management of initial proximal carious lesions using silver fluoride (SF) products in the permanent dentition of two adolescent patients with prior proximal caries progression. Both presented with multiple asymptomatic carious lesions that were identified through the use of bitewing radiographs and classified according to the ADA proximal caries classification system. Using orthodontic separators prior to the planned application of SF, most of the surfaces could then be quickly directly examined to check for surface integrity. Follow-up examinations were conducted clinically and radiographically for at least one year to monitor lesion progression. Results: None of the 25 enamel lesions (E1/E2) exhibited signs of progression after single SF application, while 2 out of 11 dentine lesions (D1) showed progression and required restorative intervention. The progressed lesions potentially had non-cleansable micro-cavitations that were either clinically undetected or not fully reached with the micro-brush in SF application. Thus, this should have been repeated or combined with SF application via soaked superfloss to potentially achieve better results. Conclusions: Single application of 38% silver fluoride directly onto active enamel lesions in juvenile permanent teeth with the prior use of orthodontic separators combined with a caries-risk-specific prevention program appears to be highly effective and should be considered as a viable minimally invasive option for patients and clinicians due to its cost-effectiveness and time efficiency

Design of New Electron Acceptor Materials for Organic Photovoltaics: Synthesis, Electron Transport, Photophysics, and Photovoltaic Properties of Oligothiophene-Functionalized Naphthalene Diimides

A homologous series of six novel oligothiophene–naphthalene diimide-based oligomer semiconductors with a donor–acceptor architecture, NDI-<i>n</i>TH (<i>n</i> = 1, 2, 3, 4) and NDI-<i>n</i>T (<i>n</i> = 2, 3), was synthesized and used to explore a set of criteria for the design of <i>non-fullerene</i> electron acceptor materials for organic solar cells. Thin films of the oligomer semiconductors had optical band gaps that varied from 2.1 eV in NDI-1TH and 1.6 eV in NDI-3TH to 1.4 eV in NDI-4TH, demonstrating good potential for light harvesting and exciton generation. The LUMO energy levels of the oligomer semiconductors were similar (ca. −4.0 eV), but the HOMO levels varied from −5.5 eV in NDI-3TH and NDI-4TH to −6.1 eV in NDI-1TH, showing that suitable energy band offsets necessary for efficient photoinduced charge transfer could be achieved with current donor polymers. Single-crystal X-ray structures of NDI-3TH and NDI-4TH showed a slipped face-to-face π-stacking with short intermolecular distances (0.321–0.326 nm), which enabled facile self-assembly of single-crystalline nanowires from solution. Spin coated thin films of NDI-<i>n</i>TH and NDI-<i>n</i>T were mostly crystalline and had field-effect electron mobilities of up to (2–9) × 10^–4 cm²/(V s). Bulk heterojunction solar cells incorporating one of the n-type oligomer semiconductors as the electron acceptor and poly(3-hexylthiophene) as the electron donor showed a power conversion efficiency of 1.5% with an open circuit voltage of 0.82 V and a bicontinuous nanoscale morphology

Design of New Electron Acceptor Materials for Organic Photovoltaics: Synthesis, Electron Transport, Photophysics, and Photovoltaic Properties of Oligothiophene-Functionalized Naphthalene Diimides

A homologous series of six novel oligothiophene–naphthalene diimide-based oligomer semiconductors with a donor–acceptor architecture, NDI-<i>n</i>TH (<i>n</i> = 1, 2, 3, 4) and NDI-<i>n</i>T (<i>n</i> = 2, 3), was synthesized and used to explore a set of criteria for the design of <i>non-fullerene</i> electron acceptor materials for organic solar cells. Thin films of the oligomer semiconductors had optical band gaps that varied from 2.1 eV in NDI-1TH and 1.6 eV in NDI-3TH to 1.4 eV in NDI-4TH, demonstrating good potential for light harvesting and exciton generation. The LUMO energy levels of the oligomer semiconductors were similar (ca. −4.0 eV), but the HOMO levels varied from −5.5 eV in NDI-3TH and NDI-4TH to −6.1 eV in NDI-1TH, showing that suitable energy band offsets necessary for efficient photoinduced charge transfer could be achieved with current donor polymers. Single-crystal X-ray structures of NDI-3TH and NDI-4TH showed a slipped face-to-face π-stacking with short intermolecular distances (0.321–0.326 nm), which enabled facile self-assembly of single-crystalline nanowires from solution. Spin coated thin films of NDI-<i>n</i>TH and NDI-<i>n</i>T were mostly crystalline and had field-effect electron mobilities of up to (2–9) × 10^–4 cm²/(V s). Bulk heterojunction solar cells incorporating one of the n-type oligomer semiconductors as the electron acceptor and poly(3-hexylthiophene) as the electron donor showed a power conversion efficiency of 1.5% with an open circuit voltage of 0.82 V and a bicontinuous nanoscale morphology

Response Surface Methodology Modelling of an Aqueous Two-Phase System for Purification of Protease from Penicillium candidum (PCA 1/TT031) under Solid State Fermentation and Its Biochemical Characterization

Penicillium candidum (PCA 1/TT031) synthesizes different types of extracellular proteases. The objective of this study is to optimize polyethylene glycol (PEG)/citrate based on an aqueous two-phase system (ATPS) and Response Surface Methodology (RSM) to purify protease from Penicillium candidum (PCA 1/TT031). The effects of different PEG molecular weights (1500–10,000 g/mol), PEG concentration (9%–20%), concentrations of NaCl (0%–10%) and the citrate buffer (8%–16%) on protease were also studied. The best protease purification could be achieved under the conditions of 9.0% (w/w) PEG 8000, 5.2% NaCl, and 15.9% sodium citrate concentration, which resulted in a one-sided protease partitioning for the bottom phase with a partition coefficient of 0.2, a 6.8-fold protease purification factor, and a yield of 93%. The response surface models displayed a significant (p ≤ 0.05) response which was fit for the variables that were studied as well as a high coefficient of determination (R2). Similarly, the predicted and observed values displayed no significant (p &gt; 0.05) differences. In addition, our enzyme characterization study revealed that Penicillium candidum (PCA 1/TT031) produced a slight neutral protease with a molecular weight between 100 and 140 kDa. The optimal activity of the purified enzyme occurred at a pH of 6.0 and at a temperature of 50 °C. The stability between different pH and temperature ranges along with the effect of chemical metal ions and inhibitors were also studied. Our results reveal that the purified enzyme could be used in the dairy industry such as in accelerated cheese ripening