A portable 28-GHz channel sounder platform and measurement results from close-to-ground field tests

This article describes a novel, bespoke, and low-cost 28-GHz RF TX and RX front end design that has been combined with a commercial Software-Defined Radio and Raspberry Pi controller to realize a portable propagation measurement system for the 28-GHz band. The complete sounder system can resolve an impulse from RX powers down to −107 dBm (3-dB impulse SNR) and the sounder TX can generate a signal of −8 dBm. Therefore, using 20-dBi antennas supports path-loss (PL) measurements of 139 dB. The sounder can resolve time-domain reflections to 33 ns in a channel measurement bandwidth of 60 MHz, producing both time-domain and frequency-domain results. The complete sounding system has been used to perform close-to-ground RF channel measurements, with propagation loss models and time-domain impulses extracted. Close-to-ground measurement is an underreported area of propagation research that is relevant for novel use-cases, such as in military applications or for mobile device-to-device communications. A key initial finding from the trials is that the PLs for 28-GHz indoor and outdoor links at circa 70 cm above ground seem close to that of free space, with very few strong reflections with delays exceeding 33 ns

Receive mode time modulated antenna array incorporating subsampling -theoretical concept and laboratory investigation

An eight element Subsampling Time Modulated Array (STMA) operating in receive mode with a carrier at 2.4 GHz is presented and demonstrated using bespoke Radio Frequency (RF) hardware. Each STMA cell incorporates subsampling functionality, with the sampling frequency significantly below the carrier frequency and requiring minimal additional hardware. By using this concept, the hardware required for a receiver incorporating an antenna array can be reduced and costs saved. STMA design equations and architecture strategies are presented, and a prototype hardware demonstrator is introduced. Laboratory measurements confirm that a received radiated signal, arranged to use the fundamental or a harmonic beam pointed at the radiating source, can be resolved from the subsampled intermediate frequency (IF) output. The concept demonstration hardware provides a measured array conversion gain of 11.4 dBi on the boresight beam, 7.8 dBi on the first positive and 11.3 dBi on the first negative harmonic beams, as resolved at the final combined IF output. The array IF output Signal to Noise and Distortion ratio is 69 dB. The dependence of array sidelobe level performance on STMA sampling switch rise time is also uncovered, though good performance with real, imperfect, hardware is still obtained

Regulating in vivo calcification of alginate microbeads

Alginate calcification has been previously reported clinically and during animal implantation; however no study has investigated the mechanism, extensively characterized the mineral, or evaluated multiple methods to regulate or eliminate mineralization. In the present study, alginate calcification was first studied in vitro: calcium-crosslinked alginate beads sequestered surrounding phosphate while forming traces of hydroxyapatite. Calcification in vivo was then examined in nude mice using alginate microbeads with and without adipose stem cells (ASCs). Variables included the delivery method, site of delivery, sex of the animal, time in vivo, crosslinking solution, and method of storage prior to delivery. Calciumcrosslinked alginate microbeads mineralized when injected subcutaneously or implanted intramuscularly after 1e6 months. More extensive analysis with histology, microCT, FTIR, XRD, and EDS showed calcium phosphate deposits throughout the microbeads with surface mineralization that closely matched hydroxyapatite found in bone. Incorporating 25 mM bisphosphonate reduced alginate calcification whereas using barium chloride eliminated mineralization. Buffering the crosslinking solution with HEPES at pH 7.3 while washing and storing samples in basal media prior to implantation also eliminated calcification in vivo. This study shows that alginate processing prior to implantation can significantly influence bulk hydroxyapatite formation and presents a method to regulate alginate calcificationAlginate calcification has been previously reported clinically and during animal implantation; however no study has investigated the mechanism, extensively characterized the mineral, or evaluated multiple methods to regulate or eliminate mineralization. In the present study, alginate calcification was first studied in vitro: calcium-crosslinked alginate beads sequestered surrounding phosphate while forming traces of hydroxyapatite. Calcification in vivo was then examined in nude mice using alginate microbeads with and without adipose stem cells (ASCs). Variables included the delivery method, site of delivery, sex of the animal, time in vivo, crosslinking solution, and method of storage prior to delivery. Calciumcrosslinked alginate microbeads mineralized when injected subcutaneously or implanted intramuscularly after 1e6 months. More extensive analysis with histology, microCT, FTIR, XRD, and EDS showed calcium phosphate deposits throughout the microbeads with surface mineralization that closely matched hydroxyapatite found in bone. Incorporating 25 mM bisphosphonate reduced alginate calcification whereas using barium chloride eliminated mineralization. Buffering the crosslinking solution with HEPES at pH 7.3 while washing and storing samples in basal media prior to implantation also eliminated calcification in vivo. This study shows that alginate processing prior to implantation can significantly influence bulk hydroxyapatite formation and presents a method to regulate alginate calcificatio

Deep Inelastic Scattering and Gauge/String Duality

We study deep inelastic scattering in gauge theories which have dual string descriptions. As a function of $gN$ we find a transition. For small $gN$, the dominant operators in the OPE are the usual ones, of approximate twist two, corresponding to scattering from weakly interacting partons. For large $gN$, double-trace operators dominate, corresponding to scattering from entire hadrons (either the original `valence' hadron or part of a hadron cloud.) At large $gN$ we calculate the structure functions. As a function of Bjorken $x$ there are three regimes: $x$ of order one, where the scattering produces only supergravity states; $x$ small, where excited strings are produced; and, $x$ exponentially small, where the excited strings are comparable in size to the AdS space. The last regime requires in principle a full string calculation in curved spacetime, but the effect of string growth can be simply obtained from the world-sheet renormalization group.Comment: 52 pages, 10 figure

ENGAGING CLINICIANS IN A PRE-IMPLEMENTATION ASSESSMENT OF THE WOMEN & PERSON-EMPOWERED COMMUNITY ACCESS FOR REPRODUCTIVE EQUITY (WE CARE) INTERVENTION

Objectives: To assess clinicians’ perspectives on WE CARE (an emergency department (ED) family planning counseling and referral intervention that uses an online health tool and community health workers) to inform intervention design for implementation. Methods: We conducted one-on-one, semi-structured interviews with Emergency Medicine, Family Medicine, and Obstetrics & Gynecology clinicians until thematic saturation. The Consolidated Framework for Implementation Research (CFIR) informed the interview guide and was used to code all transcripts. A CFIR expert conducted an external coding audit. Results: We interviewed 30 clinicians (female (77%), ED staff (47%), white (63%), and attending physicians (43%)). WE CARE was highly acceptable. Dominant CFIR domains include: (1) Clinicians suggested Design Quality and Packaging modifications, particularly the referral processes, to promote successful implementation; (2) transportation and insurance were essential Patient Needs and Resources; (3) WE CARE was Compatible with the Value of “no missed opportunity” to help patients; (4) Compatibility with Work Processes – WE CARE posed scheduling and reimbursement challenges to clinics; (5) Clinicians expressed concerns about an ED Culture of reproductive health frustrations, resistance to change, and competing priorities. Others identified the ED “safety net” culture and long wait times as assets to the intervention; (6) WE CARE had a significant Relative Advantage over the status quo. A few clinicians identified more advantageous alternatives (e.g., WE CARE in the clinic, home, or community settings); (7) Engaging Key Stakeholders throughout the hospital was a critical implementation element. Conclusions: Clinicians contextualized several implementation constructs relevant to designing and implementing an ED family planning intervention

Pirfenidone safety and adverse event management in idiopathic pulmonary fibrosis

Pirfenidone is one of two approved therapies for the treatment of idiopathic pulmonary fibrosis (IPF). Randomised controlled clinical trials an

National Institutes of Health Stroke Scale: An Alternative Primary Outcome Measure for Trials of Acute Treatment for Ischemic Stroke

Background and Purpose- The modified Rankin Scale (mRS) at 3 months is the most commonly used primary outcome measure in stroke treatment trials, but it lacks specificity and requires long-term follow-up interviews, which consume time and resources. An alternative may be the National Institutes of Health Stroke Scale (NIHSS), early after stroke. Our aim was to evaluate whether the NIHSS assessed within 1 week after treatment could serve as a primary outcome measure for trials of acute treatment for ischemic stroke. Methods- We used data from 2 randomized controlled trials of endovascular treatment for ischemic stroke: the positive MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands; N=500) and the neutral IMS (Interventional Management of Stroke) III trial (N=656). We used a causal mediation model, with linear and ordinal logistic regression adjusted for confounders, to evaluate the NIHSS 24 hours and 5 to 7 days after endovascular treatment as primary outcome measures (instead of the mRS at 3 months) in both trials. Patients who had died before the NIHSS was assessed received the maximum score of 42. NIHSS+1 was then log10-transformed. Results- In both trials, there was a significant correlation between the NIHSS at 24 hours and 5 to 7 days and the mRS. In MR CLEAN, we found a significant effect of endovascular treatment on the mRS and on the NIHSS at 24 hours and 5 to 7 days. After adjustment for NIHSS at 24 hours and 5 to 7 days, the effect of endovascular treatment on the mRS decreased from common odds ratio 1.68 (95% CI, 1.22-2.32) to respectively 1.36 (95% CI, 0.97-1.91) and 1.24 (95% CI, 0.87-1.79), indicating that treatment effect on the mRS is in large part mediated by the NIHSS. In the IMS III trial there was no treatment effect on the NIHSS at 24 hours and 5 to 7 days, corresponding with the absence of a treatment effect on the mRS. Conclusions- The NIHSS within 1 week satisfies the requirements for a surrogate end point and may be used as a primary outcome measure in trials of acute treatment for ischemic stroke, particularly in phase II(b) trials. This could reduce stroke-outcome assessment to its essentials (ie, neurological deficit), and reduce trial duration and costs. Whether and under which conditions it could be used in phase III trials requires a debate in the field with all parties. Clinical Trial Registration- URL: http://www.isrctn.com. Unique identifier: ISRCTN10888758; https://www.clinicaltrials.gov. Unique identifier: NCT00359424

Antidepressant and skeletal muscle relaxant effects of the aqueous extract of the Prosopis cineraria

The aqueous leaves extract of Prosopis cineraria (AEPC) is used traditionally for the treatment of various CNS disorder. The purpose of this study was to evaluate the extract for antidepressant and skeletal muscle relaxant activity. The antidepressant effect of the extract was evaluated using Forced swim test (FST). The immobility periods of control and treated mice were recorded. The antidepressant-like effect of tested compound was compared to that of imipramine (15 mg/kg. p.o). Muscle relaxant property was studied using rotarod apparatus and total fall off time for standard and control group was recorded. Phytochemical screening revealed the presence of saponins, flavonoids, alkaloids, glycosides, tannins and phenolic compounds. The leaf extract at doses of 200 mg/kg significantly decreased the duration of immobility time in FST. The efficacy of tested extract was found to be comparable to that of imipramine. Our results suggested that the aqueous extract of Prosopis cineraria leaves exerts antidepressant-like effect.O extrato aquoso de folhas de Prosopis cineraria (AEPC) é utilizado, tradicionalmente, para o tratamento de várias disfunções do SNC. O propósito desse estudo foi avaliar o extrato quanto às atividades antidepressiva e relaxante muscular esquelética. O efeito antidepressivo do extrato foi avaliado usando o teste do nado forçado (FST). Registraram-se os períodos de imobilidade dos camundongos controle e dos tratados. O efeito antidepressivo do composto testado foi comparado com a imipramina ((15 mg/kg. p.o). A propriedade relaxante muscular foi estudada usando o cilindro giratório e o tempo total de queda para os grupos padrão e controle foram registrados. A triagem fitoquímica revelou a presença de saponinas, flavonoides, alcaloides, glicosídeos, taninos e compostos fenólicos. O extrato da folha em doses de 200 mg/kg diminui significativamente a duração do tempo de imobilidade no FST. A eficácia do extrato testado foi comparável àquela da imipramina. Nossos resultados sugeriram que o extrato aquoso das folhas da Prosopis cineraria exerce efeito semelhante ao antidepressivo

The timing of HIV-1 infection of cells that persist on therapy is not strongly influenced by replication competency or cellular tropism of the provirus

People with HIV-1 (PWH) on antiretroviral therapy (ART) can maintain undetectable virus levels, but a small pool of infected cells persists. This pool is largely comprised of defective proviruses that may produce HIV-1 proteins but are incapable of making infectious virus, with only a fraction (~10%) of these cells harboring intact viral genomes, some of which produce infectious virus following ex vivo stimulation (i.e. inducible intact proviruses). A majority of the inducible proviruses that persist on ART are formed near the time of therapy initiation. Here we compared proviral DNA (assessed here as 3’ half genomes amplified from total cellular DNA) and inducible replication competent viruses in the pool of infected cells that persists during ART to determine if the original infection of these cells occurred at comparable times prior to therapy initiation. Overall, the average percent of proviruses that formed late (i.e. around the time of ART initiation, 60%) did not differ from the average percent of replication competent inducible viruses that formed late (69%), and this was also true for proviral DNA that was hypermutated (57%). Further, there was no evidence that entry into the long-lived infected cell pool was impeded by the ability to use the CXCR4 coreceptor, nor was the formation of long-lived infected cells enhanced during primary infection, when viral loads are exceptionally high. We observed that infection of cells that transitioned to be long-lived was enhanced among people with a lower nadir CD4+ T cell count. Together these data suggest that the timing of infection of cells that become long-lived is impacted more by biological processes associated with immunodeficiency before ART than the replication competency and/ or cellular tropism of the infecting virus or the intactness of the provirus. Further research is needed to determine the mechanistic link between immunodeficiency and the timing of infected cells transitioning to the long-lived pool, particularly whether this is due to differences in infected cell clearance, turnover rates and/or homeostatic proliferation before and after ART