455 research outputs found

    Inhibition of Intestinal Thiamin Transport in Rat Model of Sepsis.

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    ObjectivesThiamin deficiency is highly prevalent in patients with sepsis, but the mechanism by which sepsis induces thiamin deficiency is unknown. This study aimed to determine the influence of various severity of sepsis on carrier-mediated intestinal thiamin uptake, level of expressions of thiamin transporters (thiamin transporter-1 and thiamin transporter-2), and mitochondrial thiamin pyrophosphate transporter.DesignRandomized controlled study.SettingResearch laboratory at a Veterans Affairs Medical Center.SubjectsTwenty-four Sprague-Dawley rats were randomized into controls, mild, moderate, and severe sepsis with equal number of animals in each group.InterventionsSepsis was induced by cecal ligation and puncture with the cecum ligated below the cecal valve at 25%, 50%, and 75% of cecal length, defined as severe, moderate, and mild sepsis, respectively. Control animals underwent laparotomy only.Measurements and main resultsAfter 2 days of induced sepsis, carrier-mediated intestinal thiamin uptake was measured using [H]thiamin. Expressions of thiamin transporter-1, thiamin transporter-2, and mitochondrial thiamin pyrophosphate transporter proteins and messenger RNA were measured. Proinflammatory cytokines (interleukin-1ÎČ and interleukin-6) and adenosine triphosphate were also measured. Sepsis inhibited [H]thiamin uptake, and the inhibition was a function of sepsis severity. Both cell membrane thiamin transporters and mitochondrial thiamin pyrophosphate transporter expression levels were suppressed; also levels of adenosine triphosphate in the intestine of animals with moderate and severe sepsis were significantly lower than that of sham-operated controls.ConclusionsFor the first time, we demonstrated that sepsis inhibited carrier-mediated intestinal thiamin uptake as a function of sepsis severity, suppressed thiamin transporters and mitochondrial thiamin pyrophosphate transporter, leading to adenosine triphosphate depletion

    Feldenkrais Method Balance Classes Improve Balance in Older Adults: A Controlled Trial

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    The objective of this study was to investigate the effects of Feldenkrais Method balance classes on balance and mobility in older adults. This was a prospective non-randomized controlled study with pre/post measures. The setting for this study was the general community. A convenience sample of 26 community-dwelling older adults (median age 75 years) attending Feldenkrais Method balance classes formed the Intervention group. Thirty-seven volunteers were recruited for the Control group (median age 76.5 years). A series of Feldenkrais Method balance classes (the 33312Getting Grounded Gracefully33313 series), two classes per week for 10 weeks, were conducted. Main outcome measures were Activities-Specific Balance Confidence (ABC) questionnaire, Four Square Step Test (FSST), self-selected gait speed (using GAITRite instrumented gait mat). At re-testing, the Intervention group showed significant improvement on all of the measures (ABC, P = .016, FSST, P = .001, gait speed, P < .001). The Control group improved significantly on one measure (FSST, P < .001). Compared to the Control group, the Intervention group made a significant improvement in their ABC score (P = .005), gait speed (P = .017) and FSST time (P = .022). These findings suggest that Feldenkrais Method balance classes may improve mobility and balance in older adults

    “I give it everything for an hour then i sleep for four.” The experience of post-stroke fatigue during outpatient rehabilitation including the perspectives of carers : A qualitative study

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    Background: Fatigue is a debilitating post-stroke symptom negatively impacting rehabilitation. Lack of acknowledgment from carers can be additionally distressing. The purpose of this study was to describe the experience of post-stroke fatigue during outpatient rehabilitation, including the perspectives of carers. Methods: This qualitative study was guided by descriptive phenomenology within a constructivist paradigm. Semi-structured interviews were conducted with stroke survivors experiencing fatigue (Fatigue Assessment Scale >23) and attending outpatient rehabilitation. Carers were also interviewed where identified, providing insight into their own and stroke survivor experiences. Data were analyzed according to Colaizzi's analytic method. Results: Fourteen stroke survivors (50% culturally and linguistically diverse), and nine carers participated. Six themes were identified: 1. The unpredictable and unprepared uncovering of fatigue; 2. Experience and adjustment are personal 3. Being responsible for self-managing fatigue; 4. The complex juggle of outpatient stroke rehabilitation with fatigue; 5. Learning about fatigue is a self-directed problem-solving experience; 6. Family and carers can support or constrain managing fatigue. Conclusion: Despite engaging in outpatient rehabilitation, stroke survivors largely learnt to manage fatigue independent of healthcare professionals. Carers often facilitated learning, monitoring rehabilitation, daily routines and fatigue exacerbation. Conversely, family could be dismissive of fatigue and possess unrealistic expectations. Post-stroke fatigue must be considered by clinicians when delivering outpatient rehabilitation to stroke survivors. Clinicians should consistently screen for fatigue, provide flexible session scheduling, and educate about individual indicators and strategies for management. Clinicians should also explicitly engage carers who play a critical role in the management of fatigue

    Robotics to enable older adults to remain living at home

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    Given the rapidly ageing population, interest is growing in robots to enable older people to remain living at home. We conducted a systematic review and critical evaluation of the scientific literature, from 1990 to the present, on the use of robots in aged care. The key research questions were as follows: (1) what is the range of robotic devices available to enable older people to remain mobile, independent, and safe? and, (2) what is the evidence demonstrating that robotic devices are effective in enabling independent living in community dwelling older people? Following database searches for relevant literature an initial yield of 161 articles was obtained. Titles and abstracts of articles were then reviewed by 2 independent people to determine suitability for inclusion. Forty-two articles met the criteria for question 1. Of these, 4 articles met the criteria for question 2. Results showed that robotics is currently available to assist older healthy people and people with disabilities to remain independent and to monitor their safety and social connectedness. Most studies were conducted in laboratories and hospital clinics. Currently limited evidence demonstrates that robots can be used to enable people to remain living at home, although this is an emerging smart technology that is rapidly evolving.<br /

    Etude et conception d’un quadrupleur de frĂ©quence en technologie MMIC pour des applications Ă  60 GHz

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    Dans ce papier, un circuit multiplicateur de frĂ©quence par 4 est proposĂ©. Ce quadrupleur fonctionne dans la bande millimĂ©trique [56-64 GHz], il est conçu en technologie MMIC (Monolithic Microwave Integrated Circuit) en utilisant le procĂ©dĂ© technologique PH15 de la fonderie UMS. Le circuit quadrupleur de frĂ©quence sera utilisĂ© pour gĂ©nĂ©rer des frĂ©quences porteuses appartenant Ă  la bande [56-64 GHZ] permettant de rĂ©aliser la dĂ©modulation du signal RF d’une liaison de communication sans fil en bande millimĂ©trique. Ce quadrupleur fera partie du bloc rĂ©cepteur d’une liaison de communication sans fil Ă  trĂšs haut dĂ©bit en bande millimĂ©trique Ă  60 GHz

    A 5G mm-wave compact voltage-controlled oscillator in 0.25 ”m pHEMT technology

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    A 5G mm-wave monolithic microwave integrated circuit (MMIC) voltage-controlled oscillator (VCO) is presented in this paper. It is designed on GaAs substrate and with 0.25 ”m-pHEMT technology from UMS foundry and it is based on pHEMT varactors in order to achieve a very small chip size. A 0dBm-output power over the entire tuning range from 27.67 GHz to 28.91 GHz, a phase noise of -96.274 dBc/Hz and -116.24 dBc/Hz at 1 and 10 MHz offset frequency from the carrier respectively are obtained on simulation. A power consumption of 111 mW is obtained for a chip size of 0.268 mm2. According to our knowledge, this circuit occupies the smallest surface area compared to pHEMTs oscillators published in the literature

    High rejection self-oscillating up-conversion mixer for fifth-generation communications

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    This paper presents the design of a pseudomorphic high electron mobility transistor (pHEMT) self-oscillating mixer (SOM) for millimeter wave wireless communication systems. The 180° out-of-phase technique is chosen to both improve the desired lower sideband (LSB) signal and to achieve a satisfactory rejection of the unwanted signals (LO, USB and IF). This SOM is designed on the PH15 process of UMS foundry which is based on 0.15 ”m GaAs pHEMT. The signal is up-converted from 2 GHz-IF frequency to 26 GHz-LSB frequency, using an autogenerated 28 GHz-LO signal. Simulations were performed using the advanced design system (ADS) workflow. They show 6.4 dB conversion gain and a signal rejection rate of 29.7 dB for the unwanted USB signal. the chip size is 3.6 mm2

    28 GHz balanced pHEMT VCO with low phase noise and high output power performance for 5G mm-Wave systems

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    This paper presents the study and design of a balanced voltage controlled oscillator VCO for 5G wireless communication systems. This circuit is designed in monolithic microwave integrated circuit (MMIC) technology using PH15 process from UMS foundry. The VCO ensures an adequate tuning range by a single-ended pHEMT varactors configuration. The simulation results show that this circuit delivers a sinusoidal signal of output power around 9 dBm with a second harmonic rejection between 25.87 and 33.83 dB, the oscillation frequency varies between 26.46 and 28.90 GHz, the phase noise is -113.155 and -133.167 dBc/Hz respectively at 1 MHz and 10 MHz offset and the Figure of Merit is -181.06 dBc/Hz. The power consumed by the VCO is 122 mW. The oscillator layout with bias and RF output pads occupies an area of 0.515 mm2

    Etude d’une liaison ULB de type MB-OOK

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    L’ultra Large Bande (ULB) est une technologie de communication sans fil qui consiste Ă  transmettre (tĂ©lĂ©communications) ou Ă  recueillir (radar) des donnĂ©es en utilisant des signaux impulsionnels de courte durĂ©e et ayant donc un large spectre de frĂ©quences. Elle a suscitĂ© beaucoup d’intĂ©rĂȘt en radar et tĂ©lĂ©communications. Elle semble ĂȘtre un candidat viable en particulier pour les communications indoor offrant des dĂ©bits binaires trĂšs Ă©levĂ©s (> 100 Mbits/s) pour les courtes distances (10 Ă  50 m). Dans le domaine des transmissions ULB, deux grandes familles de formes d’onde sont en concurrence. Il s’agit d’une part des formes d’onde impulsionnelles, et d’autre part des formes d’onde multi-porteuses (MBOA : Multiband-OFDM Alliance). Une troisiĂšme forme d’onde a Ă©tĂ© proposĂ©e rĂ©cemment par Mitsubishi, c’est la solution multi-bande impulsionnelle : ULB MB-OOK, qui regroupe les avantages des deux formes d’onde. Dans cet article, nous prĂ©sentons les rĂ©sultats de simulation et de mesure d’une liaison ULB MB-OOK dans le domaine temporel en mettant en Ă©vidence l’influence des diffĂ©rentes parties de l’architecture sur la dynamique du signal ULB le long de la liaison. Nous prĂ©sentons aussi nos travaux de dĂ©veloppement d’un circuit gĂ©nĂ©rateur d’impulsions monocycles gaussiennes, qui est l’un des Ă©lĂ©ments clĂ©s d’une liaison ULB MBOOK
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