Monolayer molybdenum disulfide (MoS2) has emerged as a model system for studying many-body physics because the low dimensionality reduces screening leading to tightly bound states stable at room ...temperature. Further, the many-body states possess a pseudo-spin degree of freedom that corresponds with the two direct-gap valleys of the band structure, which can be optically manipulated. Here we focus on one bound state, the negatively charged trion. Unlike excitons, trions can radiatively decay with non-zero momentum by kicking out an electron, resulting in an asymmetric trion photoluminescence (PL) peak with a long low-energy tail and peak position that differs from the zero momentum trion energy. The asymmetry of the trion PL peak and resulting peak red-shift depends both on the trion size and a temperature-dependent contribution. Ignoring the trion asymmetry will result in over estimating the trion binding energy by nearly 20 meV at room temperature. We analyze the temperature-dependent PL to reveal the effective trion size, consistent with the literature, and the temperature dependence of the band gap and spin-orbit splitting of the valence band. This is the first time the temperature-dependence of the trion PL has been analyzed with such detail in any system.
We demonstrate the continuous and reversible tuning of the optical band gap of suspended monolayer MoS2 membranes by as much as 500 meV by applying very large biaxial strains. By using chemical vapor ...deposition (CVD) to grow crystals that are highly impermeable to gas, we are able to apply a pressure difference across suspended membranes to induce biaxial strains. We observe the effect of strain on the energy and intensity of the peaks in the photoluminescence (PL) spectrum and find a linear tuning rate of the optical band gap of 99 meV/%. This method is then used to study the PL spectra of bilayer and trilayer devices under strain and to find the shift rates and Grüneisen parameters of two Raman modes in monolayer MoS2. Finally, we use this result to show that we can apply biaxial strains as large as 5.6% across micron-sized areas and report evidence for the strain tuning of higher level optical transitions.
Abstract
Background
Plasmodium vivax controlled human malaria infection (PvCHMI) is an important tool for evaluation of drugs, vaccines, and pathologies associated with this parasite. However, there ...are few data on safety due to limited numbers of PvCHMIs performed.
Methods
We report clinical and laboratory data, including hematological and biochemical profiles and adverse events (AEs), following mosquito bite-induced PvCHMI in malaria-naive study participants. Malaria diagnosis and treatment initiation was based on microscopic analysis of Giemsa-stained slides. Exploratory molecular assays were used to detect parasites using real-time polymerase chain reaction (PCR).
Results
AEs were mild to moderate and no study-related severe AEs were observed in any study participants. The majority of symptoms were transient, resolving within 48 hours. Molecular diagnostic methods detected parasitemia in 100% of study participants before malaria diagnosis using microscopy. Of reported AEs, microscopy detected 67%–100%, quantitative PCR 79%–100%, and quantitative real-time reverse-transcription PCR 96%–100% of study participants prior to appearance of symptoms. Almost all symptoms appeared after initiation of treatment, likely as known consequence of drug treatment.
Conclusions
PvCHMI is safe with the majority of infections being detected prior to appearance of clinical symptoms, which can be further alleviated by using sensitive molecular methods for clinical diagnosis.
Clinical Trials Registration. NCT01157897.
Mosquito bite-induced P. vivax controlled human malaria infection results in moderate or mild clinical symptoms and transient deviations in biochemical and hematological parameters. Utilizing molecular diagnostic methods alleviates these further, making this a safe model to evaluate biology and interventions.
Response to Odedra et al Kamau, Edwin; Bennett, Jason W; Yadava, Anjali
The Journal of infectious diseases,
03/2022, Letnik:
225, Številka:
5
Journal Article
Blood and surveillance cultures from an injured service member from Ukraine grew Acinetobacter baumannii, Klebsiella pneumoniae, Enterococcus faecium, and 3 distinct Pseudomonas aeruginosa strains. ...Isolates were nonsusceptible to most antibiotics and carried an array of antibiotic resistant genes, including carbapenemases (bla
, bla
, bla
, bla
, bla
) and 16S methyltransferases (armA and rmtB4).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Primaquine is used to eradicate the hepatic or hypnozoite form of Plasmodium vivax that may lead to relapse of infection. Host genetic factors may play a role in the activity of primaquine therapy.
...To the Editor:
Primaquine is the only medication approved by the Food and Drug Administration to eradicate the hypnozoites of
Plasmodium vivax,
but relapses of
P. vivax
malaria due to drug failure occur.
1
Human cytochrome P-450 isoenzyme 2D6 (CYP2D6) may be a key enzyme involved in metabolizing primaquine into redox-active metabolites against hypnozoites in the liver.
2
,
3
As part of a phase 1 clinical trial of a vaccine against
P. vivax
(Study of VMP001 and AS01B in Healthy Malaria-Naive Adults; ClinicalTrials.gov number, NCT01157897), 33 participants were exposed to
P. vivax
sporozoites from the bites of infected mosquitoes. Parasitemia developed in . . .
A vaccine to prevent infection and disease caused by Plasmodium vivax is needed both to reduce the morbidity caused by this parasite and as a key component in efforts to eradicate malaria worldwide. ...Vivax malaria protein 1 (VMP001), a novel chimeric protein that incorporates the amino- and carboxy- terminal regions of the circumsporozoite protein (CSP) and a truncated repeat region that contains repeat sequences from both the VK210 (type 1) and the VK247 (type 2) parasites, was developed as a vaccine candidate for global use.
We conducted a first-in-human Phase 1 dose escalation vaccine study with controlled human malaria infection (CHMI) of VMP001 formulated in the GSK Adjuvant System AS01B. A total of 30 volunteers divided into 3 groups (10 per group) were given 3 intramuscular injections of 15 μg, 30 μg, or 60 μg respectively of VMP001, all formulated in 500 μL of AS01B at each immunization. All vaccinated volunteers participated in a P. vivax CHMI 14 days following the third immunization. Six non-vaccinated subjects served as infectivity controls.
The vaccine was shown to be well tolerated and immunogenic. All volunteers generated robust humoral and cellular immune responses to the vaccine antigen. Vaccination did not induce sterile protection; however, a small but significant delay in time to parasitemia was seen in 59% of vaccinated subjects compared to the control group. An association was identified between levels of anti-type 1 repeat antibodies and prepatent period.
This trial was the first to assess the efficacy of a P. vivax CSP vaccine candidate by CHMI. The association of type 1 repeat-specific antibody responses with delay in the prepatency period suggests that augmenting the immune responses to this domain may improve strain-specific vaccine efficacy. The availability of a P. vivax CHMI model will accelerate the process of P. vivax vaccine development, allowing better selection of candidate vaccines for advancement to field trials.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background:
Pain of a moderate or severe intensity affects over half of patients with advanced cancer and remains undertreated in at least one-third of these patients.
Aim:
The aim of this study was ...to provide a pragmatic overview of the evidence supporting the use of interventions in pain management in advanced cancer and to identify where encouraging preliminary results are demonstrated but further research is required.
Design:
A scoping review approach was used to examine the evidence supporting the use of guideline-recommended interventions in pain management practice.
Data sources:
National or international guidelines were selected if they described pain management in adult cancer patients and were written within the last 5 years in English. The Cochrane Database of Systematic Reviews (January 2014 to January 2019) was searched for ‘cancer’ AND ‘pain’ in the title, abstract or keywords. A MEDLINE search was also made.
Results:
A strong opioid remains the drug of choice for treating moderate or severe pain. Bisphosphonates and radiotherapy are also effective for cancer-related bone pain. Optimal management requires a tailored approach, support for self-management and review of treatment outcomes. There is likely a role for non-pharmacological approaches. Paracetamol should not be used in patients taking a strong opioid to treat pain. Cannabis-based medicines are not recommended. Weak opioids, ketamine and lidocaine are indicated in specific situations only.
Conclusion:
Interventions commonly recommended by guidelines are not always supported by a robust evidence base. Research is required to evaluate the efficacy of non-steroidal anti-inflammatory drugs, anti-convulsants, anti-depressants, corticosteroids, some invasive anaesthetic techniques, complementary therapies and transcutaneous electrical nerve stimulation.
A protracted outbreak of New Delhi metallo-β-lactamase (NDM)-producing carbapenem-resistant
started in Tuscany, Italy, in November 2018 and continued in 2020 and through 2021. To understand the ...regional emergence and transmission dynamics over time, we collected and sequenced the genomes of 117 extensively drug-resistant, NDM-producing
isolates cultured over a 20-mo period from 76 patients at several healthcare facilities in southeast Tuscany. All isolates belonged to high-risk clone ST-147 and were typically nonsusceptible to all first-line antibiotics. Albeit sporadic, resistances to colistin, tigecycline, and fosfomycin were also observed as a result of repeated, independent mutations. Genomic analysis revealed that ST-147 isolates circulating in Tuscany were monophyletic and highly genetically related (including a network of 42 patients from the same hospital and sharing nearly identical isolates), and shared a recent ancestor with clinical isolates from the Middle East. While the
gene was carried by an IncFIB-type plasmid, our investigations revealed that the ST-147 lineage from Italy also acquired a hybrid IncFIB/IncHIB-type plasmid carrying the 16S methyltransferase
gene as well as key virulence biomarkers often found in hypervirulent isolates. This plasmid shared extensive homologies with mosaic plasmids circulating globally including from ST-11 and ST-307 convergent lineages. Phenotypically, the carriage of this hybrid plasmid resulted in increased siderophore production but did not confer virulence to the level of an archetypical, hypervirulent
in a subcutaneous model of infection with immunocompetent CD1 mice. Our findings highlight the importance of performing genomic surveillance to identify emerging threats.
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