542 research outputs found
An Improved molecular tool for distinguishing monoecious and dioedious Hydrilla
Two biotypes of hydrilla [Hydrilla verticillata(L.f.) Royle]
occur in the United States, a dioecious type centered
in the southeast and a monoecious type in the central Atlantic and northeastern states. Ecosystem managers need tools to distinguish the types as the ranges of each type expand and begin to overlap. A molecular tool using the randomly amplified polymorphic DNA (RAPD) procedure is available but its use is limited by a need for reference samples. We describe an alternative molecular tool which uses “universal primers” to sequence the trnL intron and trnL-F intergenic spacer of the chloroplast genome. This sequence yields three differences between the biotypes (two gaps and one single nucleotide polymorphism). A primer has been designed which ends in a gap that shows up only in the dioecious plant. A polymerase chain reaction (PCR) using this primer produces a product for the monoecious but not the dioecious plant
Countering Eavesdroppers with Meta-learning-based Cooperative Ambient Backscatter Communications
This article introduces a novel lightweight framework using ambient
backscattering communications to counter eavesdroppers. In particular, our
framework divides an original message into two parts: (i) the active-transmit
message transmitted by the transmitter using conventional RF signals and (ii)
the backscatter message transmitted by an ambient backscatter tag that
backscatters upon the active signals emitted by the transmitter. Notably, the
backscatter tag does not generate its own signal, making it difficult for an
eavesdropper to detect the backscattered signals unless they have prior
knowledge of the system. Here, we assume that without decoding/knowing the
backscatter message, the eavesdropper is unable to decode the original message.
Even in scenarios where the eavesdropper can capture both messages,
reconstructing the original message is a complex task without understanding the
intricacies of the message-splitting mechanism. A challenge in our proposed
framework is to effectively decode the backscattered signals at the receiver,
often accomplished using the maximum likelihood (MLK) approach. However, such a
method may require a complex mathematical model together with perfect channel
state information (CSI). To address this issue, we develop a novel deep
meta-learning-based signal detector that can not only effectively decode the
weak backscattered signals without requiring perfect CSI but also quickly adapt
to a new wireless environment with very little knowledge. Simulation results
show that our proposed learning approach, without requiring perfect CSI and
complex mathematical model, can achieve a bit error ratio close to that of the
MLK-based approach. They also clearly show the efficiency of the proposed
approach in dealing with eavesdropping attacks and the lack of training data
for deep learning models in practical scenarios
Combination Antifungal Therapy for Cryptococcal Meningitis
Background
Combination antifungal therapy (amphotericin B deoxycholate and flucytosine) is the recommended treatment for cryptococcal meningitis but has not been shown to reduce mortality, as compared with amphotericin B alone. We performed a randomized, controlled trial to determine whether combining flucytosine or high-dose fluconazole with high-dose amphotericin B improved survival at 14 and 70 days.
Methods
We conducted a randomized, three-group, open-label trial of induction therapy for cryptococcal meningitis in patients with human immunodeficiency virus infection. All patients received amphotericin B at a dose of 1 mg per kilogram of body weight per day; patients in group 1 were treated for 4 weeks, and those in groups 2 and 3 for 2 weeks. Patients in group 2 concurrently received flucytosine at a dose of 100 mg per kilogram per day for 2 weeks, and those in group 3 concurrently received fluconazole at a dose of 400 mg twice daily for 2 weeks.
Results
A total of 299 patients were enrolled. Fewer deaths occurred by days 14 and 70 among patients receiving amphotericin B and flucytosine than among those receiving amphotericin B alone (15 vs. 25 deaths by day 14; hazard ratio, 0.57; 95% confidence interval [CI], 0.30 to 1.08; unadjusted P=0.08; and 30 vs. 44 deaths by day 70; hazard ratio, 0.61; 95% CI, 0.39 to 0.97; unadjusted P=0.04). Combination therapy with fluconazole had no significant effect on survival, as compared with monotherapy (hazard ratio for death by 14 days, 0.78; 95% CI, 0.44 to 1.41; P=0.42; hazard ratio for death by 70 days, 0.71; 95% CI, 0.45 to 1.11; P=0.13). Amphotericin B plus flucytosine was associated with significantly increased rates of yeast clearance from cerebrospinal fluid (−0.42 log10 colony-forming units [CFU] per milliliter per day vs. −0.31 and −0.32 log10 CFU per milliliter per day in groups 1 and 3, respectively; P<0.001 for both comparisons). Rates of adverse events were similar in all groups, although neutropenia was more frequent in patients receiving a combination therapy.
Conclusions
Amphotericin B plus flucytosine, as compared with amphotericin B alone, is associated with improved survival among patients with cryptococcal meningitis. A survival benefit of amphotericin B plus fluconazole was not found
Optimization of Multiplex-PCR Technique To Determine Azf Deletions in infertility Male Patients
Tung Nguyen Thanh,1 Sang Trieu Tien,2 Phong Nguyen Van,2 Son Dang Thai,3 Thuc Luong Cong,4 Tuan Dinh Le,5 Son Tien Nguyen,5 Tuan Tran Van,1 Hoang Huy Duong,6 Tien Minh Bui,7 Kien Trung Nguyen7 1Military Institute of Clinical Embryology and Histology, Vietnam Military Medical University, Hanoi, 100000, Vietnam; 2Department of Biology and Medical Genetics, Vietnam Military Medical University, Hanoi, 100000, Vietnam; 3Institute of Biological and Food Technology, Hanoi Open University, Hanoi, 100000, Vietnam; 4Cardiovascular Center, Military Hospital 103, Vietnam Military Medical University, Hanoi, 100000, Vietnam; 5Department of Rheumatology and Endocrinology, Military Hospital 103, Vietnam Military Medical University, Hanoi, 100000, Vietnam; 6Department of Neurology, Thai Binh University of Medicine and Pharmacy, Thai Binh, 410000, Vietnam; 7Department of Obstetrics and Gynecology, Thai Binh University of Medicine and Pharmacy, Thai Binh, 410000, VietnamCorrespondence: Sang Trieu Tien, Department of Biology and Medical Genetics, Vietnam Military Medical University, Hanoi, 100000, Vietnam, Email [email protected]: To optimize the multiplex polymerase chain reaction (M-PCR) technique to diagnose microdeletions of azoospermia factors (AZF) on the Y chromosome and initially apply the technique to diagnose male patients with sperm density less than 5× 106 million sperm/mL was assigned to do a test to check for AZF microdeletions on the Y chromosome.Methods: Based on the positive control samples which belong to male subjects who have had 2 healthy children without any assisted reproductive technologies, the M-PCR method was developed to detect simultaneously and accurately AZF microdeletions on 32 male patients with sperm densities below 5× 106 million sperm/mL of semen at the Department of Biology and Medical Genetics – Vietnam Military Medical University.Results: Successful optimization of the M-PCR technique including 7 reactions arranged according to each AZFabc region using 24 STS/gene on the Y chromosome. Initial application to diagnose AZF deletion on 32 azoospermic and oligospermic men reveals that AZFa deletion accounts for 6.25% (2/32); deletion of all 3 regions AZFa,b,c with 18.75% (6/32 cases); The combined deletion rate of AZFb,c is highest, accounting for 56.24% (18/32 patients).Conclusion: Successfully optimized the M-PCR technique in identifying AZF microdeletions using 24 sequence tagged sites (STS)/gene for azoospermic and oligozoospermic men. The M-PCR technique has great potential in the application of AZF deletion diagnosis.Keywords: male infertility, azoospermia factors, AZF, multiplex polymerase chain reaction, M-PCR, sequence tagged sites, ST
Short and long term retention in antiretroviral care in health facilities in rural Malawi and Zimbabwe.
Despite the successful scale-up of ART services over the past years, long term retention in ART care remains a major challenge, especially in high HIV prevalence and resource-limited settings. This study analysed the short (<12 months) and long (>12 months) term retention on ART in two ART programmes in Malawi (Thyolo district) and Zimbabwe (Buhera district)
Enabling Technologies for Web 3.0: A Comprehensive Survey
Web 3.0 represents the next stage of Internet evolution, aiming to empower
users with increased autonomy, efficiency, quality, security, and privacy. This
evolution can potentially democratize content access by utilizing the latest
developments in enabling technologies. In this paper, we conduct an in-depth
survey of enabling technologies in the context of Web 3.0, such as blockchain,
semantic web, 3D interactive web, Metaverse, Virtual reality/Augmented reality,
Internet of Things technology, and their roles in shaping Web 3.0. We commence
by providing a comprehensive background of Web 3.0, including its concept,
basic architecture, potential applications, and industry adoption.
Subsequently, we examine recent breakthroughs in IoT, 5G, and blockchain
technologies that are pivotal to Web 3.0 development. Following that, other
enabling technologies, including AI, semantic web, and 3D interactive web, are
discussed. Utilizing these technologies can effectively address the critical
challenges in realizing Web 3.0, such as ensuring decentralized identity,
platform interoperability, data transparency, reducing latency, and enhancing
the system's scalability. Finally, we highlight significant challenges
associated with Web 3.0 implementation, emphasizing potential solutions and
providing insights into future research directions in this field
Allogeneic administration of human umbilical cord-derived mesenchymal stem/stromal cells for bronchopulmonary dysplasia: preliminary outcomes in four Vietnamese infants
Background: Bronchopulmonary dysplasia (BPD) is a severe condition in premature infants that compromises lung function and necessitates oxygen support. Despite major improvements in perinatal care minimizing the devastating effects, BPD remains the most frequent complication of extreme preterm birth. Our study reports the safety of the allogeneic administration of umbilical cord-derived mesenchymal stem/stromal cells (allo-UC-MSCs) and the progression of lung development in four infants with established BPD. Methods: UC tissue was collected from a healthy donor, followed by propagation at the Stem Cell Core Facility at Vinmec Research Institute of Stem Cell and Gene Technology. UC-MSC culture was conducted under xeno- and serum-free conditions. Four patients with established BPD were enrolled in this study between May 25, 2018, and December 31, 2018. All four patients received two intravenous doses of allo-UC-MSCs (1 million cells/kg patient body weight (PBW) per dose) with an intervening interval of 7 days. Safety and patient conditions were evaluated during hospitalization and at 7 days and 1, 6 and 12 months postdischarge. Results: No intervention-associated severe adverse events or prespecified adverse events were observed in the four patients throughout the study period. At the time of this report, all patients had recovered from BPD and were weaned off of oxygen support. Chest X-rays and CT scans confirmed the progressive reductions in fibrosis. Conclusions: Allo-UC-MSC administration is safe in preterm infants with established BPD. Trial registration This preliminary study was approved by the Vinmec International Hospital Ethics Board (approval number: 88/2019/QĐ-VMEC; retrospectively registered March 12, 2019)
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