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1.
J Res Natl Inst Stand Technol ; 126: 126054, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-38469437

RESUMEN

A portable calorimeter for direct realization of absorbed dose in medical computed tomography (CT) procedures was constructed and tested in a positron emission tomography (PET) CT scanner. The calorimeter consists of two small thermistors embedded in a polystyrene (PS) cylindrical "core" (1.5 cm diameter) that can be inserted into a cylindrical high-density polyethylene (HDPE) phantom (30 cm diameter). The cylindrical design of core and phantom allows coaxial alignment of the system with the scanner rotation axis, which is necessary to minimize variations in dose that would otherwise occur as the X-ray source is rotated during scanning operations. The core can be replaced by a cylindrical ionization chamber for comparing dose measurement results. Measurements using the core and a calibrated thimble ionization chamber were carried out in a beam of 6 MV X-rays from a clinical accelerator and in 120 kV X-rays from a CT scanner. Doses obtained from the calorimeter and chamber in the 6 MV beam exhibited good agreement over a range of dose rates from 0.8 Gy/min to 4 Gy/min, with negligible excess heat. For the CT beam, as anticipated for these X-ray energies, the calorimeter response was complicated by excess heat from device components. Analyses done in the frequency domain and time domain indicated that excess heat increased calorimetric temperature rise by a factor of about 15. The calorimeter's response was dominated by dose to the thermistor, which contains high-atomic-number elements. Therefore, for future construction of calorimeters for CT beams, lower-atomic-number temperature sensors will be needed. These results serve as a guide for future alternative design of calorimeters toward a calorimetry absorbed dose standard for diagnostic CT.

2.
Acta Chir Plast ; 62(1-2): 50-52, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32911943

RESUMEN

Some patients undergoing breast reconstruction with acellular dermal matrices (ADMs) develop postoperative erythema overlying their ADM grafts named red breast syndrome (RBS). To the best of our knowledge this entity has never been related to the use of a synthetic mesh. We present a case of a 61-year-old patient who underwent bilateral nipple-sparing prophylactic mastectomy because of BRCA-1 gene mutation. The patient was reconstructed with a direct-to-implant approach, and the implants were covered with a polyglycolic acid mesh. Twenty days after the reconstruction, she presented with a blanching erythema of both reconstructed breasts without signs of infection on the area covered by the mesh. The patient denied symptoms like fever or tenderness and presented with no clinical signs of infection. Her laboratory tests were within normal range. We decided to watch and wait. The patient continued strict controls in the outpatient setting. Gradually, the erythema begun to disappear and it resolved spontaneously. RBS has only been described with the use of ADMs, but since in this case the mesh was made of polyglycolic acid, we suggest RBS should be considered either with the use of biological or synthetic meshes. The importance of its differential diagnosis resides in distinguishing it from an infection.


Asunto(s)
Eritema/etiología , Mamoplastia , Mallas Quirúrgicas , Implantación de Mama , Implantes de Mama/efectos adversos , Neoplasias de la Mama/cirugía , Femenino , Humanos , Mamoplastia/efectos adversos , Mastectomía , Persona de Mediana Edad , Polietilenglicoles , Mallas Quirúrgicas/efectos adversos
3.
Eur Spine J ; 26(9): 2441-2449, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28676980

RESUMEN

PURPOSE: Previous studies have demonstrated that total cervical disc replacement (cTDR) represents a viable treatment alternative to the 'gold standard' anterior cervical discectomy and fusion for the treatment of well-defined cervical pathologies at short- and mid-term follow-up (FU). However, the implementation and acceptance of a non-fusion philosophy is closely associated with its avoidance of adjacent segment degeneration. Proof of the functional sustainability and clinical improvement of symptoms at long-term FU is still pending. The aim of this ongoing prospective study was to investigate the clinical and radiological results of cTDR at long-term FU. METHODS: 50 patients were treated surgically within a non-randomised prospective study framework with cTDR (ProDisc C™, Synthes, Paoli, PA, USA). Patients were examined preoperatively followed by routine clinical and radiological examinations at 1, 5 and 10 years after surgery, respectively. In addition to the clinical scores, conventional X-ray images of the cervical spine were taken in anteroposterior and lateral view as well as flexion/extension images. Clinical outcome scores included parameters such as the Neck Disability Index (NDI), Visual Analogue Scale (VAS), arm and neck pain self-assessment questionnaires as well as subjective patient satisfaction rates. The radiological outcome variables included the range of motion (ROM) of the implanted prosthesis between maximum flexion and extension images, the occurrence of heterotopic ossifications and radiographic signs of adjacent segment degenerative changes. The reoperation rate following cTDR was recorded as a secondary outcome variable. RESULTS: A significant and maintained clinical improvement of all clinical outcome scores was observed after a mean FU of 10.2 years (VASarm 6.3-2.1; VASneck 6.4-1.9; NDI 21-6; p < 0.05). An increase in the incidence and the extent of heterotopic ossifications was noted during the post-operative course with a significant influence on the function of the prosthesis, which, however, did not reveal any detrimental effect on the patients' clinical symptomatology. Prosthesis mobility declined from 9.0° preoperatively and 9.1° at 1 year FU to 7.7° and 7.6° at the five- and ten-year FU examinations, respectively. Radiological signs of adjacent segment degeneration were detected in 13/38 (35.7%), however, in only 3/38 (7.9%) patients this radiological changes were associated with clinical symptoms requiring conservative treatment. Intraoperative technical failure in two cases required interbody fusion with a cage (2/50). One patient (1/48, 2.1%) treated this motion device had revision surgery at the index level. CONCLUSION: Cervical total disc replacement with ProDisc C demonstrated a significant and maintained improvement of all clinical outcome parameters at a follow-up of ≥10 years. The present long-term data reveal that with an exceptionally low implant-related reoperation rate and low symptomatic adjacent segment degeneration rate, cTDR may be regarded as a safe and viable treatment option.


Asunto(s)
Vértebras Cervicales/cirugía , Degeneración del Disco Intervertebral/cirugía , Reeemplazo Total de Disco/métodos , Adulto , Anciano , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/fisiopatología , Discectomía/métodos , Femenino , Estudios de Seguimiento , Humanos , Degeneración del Disco Intervertebral/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Dolor de Cuello/etiología , Dimensión del Dolor/métodos , Satisfacción del Paciente , Periodo Posoperatorio , Estudios Prospectivos , Prótesis e Implantes , Diseño de Prótesis , Radiografía , Rango del Movimiento Articular , Reoperación/estadística & datos numéricos , Reeemplazo Total de Disco/instrumentación , Resultado del Tratamiento
4.
Artículo en Inglés | MEDLINE | ID: mdl-34877089

RESUMEN

The goal of this study was to compare volumetric analysis in computed tomography (CT) with the length measurement prescribed by the Response Evaluation Criteria in Solid Tumors (RECIST) for a system with known mass and unknown shape. We injected 2 mL to 4 mL of water into vials of sodium polyacrylate and into disposable diapers. Volume measurements of the sodium polyacrylate powder were able to predict both mass and proportional changes in mass within a 95 % prediction interval of width 12 % and 16 %, respectively. The corresponding figures for RECIST were 102 % and 82 %.

5.
Clin Orthop Relat Res ; 474(9): 2020-7, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27160744

RESUMEN

BACKGROUND: During the last 20 years several less-invasive anterior approaches to the lumbar spine have become standard, including the extreme lateral transpsoas approach. Although it is associated with a lower risk of vascular injury compared with anterior midline approaches, neuromonitoring is considered mandatory to avoid neurologic complications. Interestingly, despite neuromonitoring, the reported risk of neurologic deficits with the extreme lateral transpsoas approach is greater than observed with other anterior approaches. An alternative lateral, oblique, psoas-sparing approach, recently named the oblique lumbar interbody fusion, uses the anatomic pathway between the abdominal vessels anteriorly and the lumbar plexus laterally to decrease the risk of neurologic and vascular injury; however, as yet, little on this new approach has been reported. QUESTIONS/PURPOSES: We asked: what proportion of patients experienced (1) perioperative complications (overall complications), (2) vascular complications, and (3) neurologic complications after less-invasive anterior lumbar interbody fusion through the oblique lumbar interbody approach at one high-volume center? METHODS: We performed a chart review of intra- and perioperative complications of all patients who had undergone minimally invasive anterior lumbar interbody fusion through a lateral psoas-sparing approach from L1 to L5 during a 12-year period (1998-2010). During the study period, the oblique, psoas-sparing approach was the preferred approach of the participating surgeons in this study, and it was performed in 812 patients, all of whom are studied here, and all of whom have complete data for assessment of the short-term (inpatient-only) complications that we studied. In general, we performed this approach whenever possible, although it generally was avoided when a patient previously had undergone an open retro- or transperitoneal abdominal procedure, or previous implantation of hernia mesh in the abdomen. During the study period, posterior fusion techniques were used in an additional 573 patients instead of the oblique lumbar interbody fusion when we needed to decompress the spinal canal beyond what is possible through the anterior approach. In case of spinal stenosis calling for fusion in combination with a high disc space, severe endplate irregularity, or severe biomechanical instability, we combined posterior decompression with oblique lumbar interbody fusion in 367 patients. Complications were evaluated by an independent observer who was not involved in the decision-making process, the operative procedure, nor the postoperative care by reviewing the inpatient records and operative notes. RESULTS: A total of 3.7% (30/812) of patients who underwent the oblique lumbar interbody fusion experienced a complication intraoperatively or during the hospital stay. During the early postoperative period there were two superficial (0.24%) and three deep (0.37%) wound infections and five superficial (0.62%) and six deep (0.86%) hematomas. There were no abdominal injuries or urologic injuries. The percentage of vascular complications was 0.37% (n = 3). The percentage of neurologic complications was 0.37% (n = 3). CONCLUSIONS: The risk of vascular complications after oblique lumbar interbody fusion seems to be lower compared with reported risk for anterior midline approaches, and the risk of neurologic complications after oblique lumbar interbody fusion seems to be lower than what has been reported with the extreme lateral transpsoas approach; however, we caution readers that head-to-head studies will need to be performed to confirm our very preliminary comparisons and results with the oblique psoas-sparing approach. Similarly, future studies will need to evaluate this approach in terms of later-presenting complications, such as infection and pseudarthrosis formation, which could not be assessed using this inpatient-only approach. Nevertheless, with the results of this study the oblique psoas-sparing approach can be described as a less-invasive alternative for anterior lumbar fusion surgery from L1 to L5 with a low risk of vascular and neurologic damage and without costly intraoperative neuromonitoring tools. LEVEL OF EVIDENCE: Level IV, therapeutic study.


Asunto(s)
Descompresión Quirúrgica/métodos , Vértebras Lumbares/cirugía , Músculos Psoas/cirugía , Fusión Vertebral/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Descompresión Quirúrgica/efectos adversos , Femenino , Alemania , Hospitales de Alto Volumen , Humanos , Vértebras Lumbares/fisiopatología , Masculino , Registros Médicos , Persona de Mediana Edad , Traumatismos de los Nervios Periféricos/etiología , Estudios Retrospectivos , Factores de Riesgo , Fusión Vertebral/efectos adversos , Infección de la Herida Quirúrgica/etiología , Factores de Tiempo , Resultado del Tratamiento , Lesiones del Sistema Vascular/etiología , Adulto Joven
6.
Res Sports Med ; 24(4): 395-406, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27537067

RESUMEN

The purpose of this study is to identify several responsible parameters for back pain (BP) in youth soccer players to create a risk assessment tool for early prevention. An iPad-based survey was used to screen for parameters in a cross-sectional study. This questionnaire includes items regarding anthropometric data, training habits and sports injuries and was put into practice with 1110 athletes. Sex (odds ratio (OR): 1.84), age group (1.48) and playing surface (1.56) were significantly associated with BP. A history of injuries especially to the spine and hip/groin increased the likelihood for evolving recurrent BP (1.74/1.40). Overall 15 factors seem to influence the appearance of pain and were integrated into a feasible nomogram. The nomogram provides a practical tool to identify the risks of developing BP for youth soccer players. Although most factors we identified are non-modifiable, this method allows to rank the importance of factors and especially their prevention treatments for athletes.


Asunto(s)
Dolor de Espalda/etiología , Encuestas Epidemiológicas , Fútbol , Adolescente , Dolor de Espalda/diagnóstico , Dolor de Espalda/prevención & control , Niño , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Masculino , Nomogramas , Dimensión del Dolor , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Fútbol/lesiones , Fútbol/fisiología , Adulto Joven
7.
Eur Spine J ; 24(4): 838-51, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25476136

RESUMEN

PURPOSE: The purpose of this study was to assess the mid-term clinical and radiological results as well as patient safety in terms of complication and reoperation rates in patients treated with a novel anterior stand-alone fusion (ASAF) device (Synfix-LR, DePuy Synthes, West Chester, PA, USA) in a cohort of patients with predominant and intractable low back pain originating from monosegmental degenerative disc disease at the lumbosacral junction. METHODS: Clinical outcome scores visual analog scale (VAS), Oswestry disability index (ODI) and patient satisfaction rates were acquired within the framework of an ongoing single-center prospective clinical trial. Evaluation of radiological data included segmental and global lumbar lordosis, neuroforaminal height and width. Interbody fusion was assessed from post-operative CT scans. The minimum follow-up (FU) was 12 months. RESULTS: 71 out of an initial 77 patients were available for final FU (92.2 % FU rate) after a mean FU of 35.1 months (range 12.0-85.5 months). The overall results revealed a highly significant improvement from baseline VAS and ODI levels (p < 0.0001). 77.5 % (n = 55/71) of all patients reported a 'highly satisfactory' (n = 37/71; 52.1 %) or a 'satisfactory' (n = 18/71; 25.4 %) outcome; 22.5 % of patients were not satisfied. The overall complication rate was 12.7 % (n = 9/71). Two cases required post-operative revision surgery (2.8 %). Radiographical analysis demonstrated a highly significant increase of segmental lordosis from 16.1° to 26.7° (p < 0.0001). A high rate of solid interbody fusion was confirmed in 97.3 % of all cases (n = 36/37). CONCLUSION: The current study delineates satisfactory clinical results following ASAF at the lumbosacral junction. Patient safety was demonstrated with acceptable complication and low reoperation rates. Radiological data demonstrated a significant reconstruction of lordosis at the lumbosacral junction. Solid interbody fusion was achieved in 97.3 % of all cases in a highly selected cohort with optimal predisposition for fusion. ASAF may serve to avoid a variety of negative side effects for a considerable number of patients which, otherwise, would have been candidates for posterior instrumented fusion techniques.


Asunto(s)
Degeneración del Disco Intervertebral/cirugía , Dolor de la Región Lumbar/cirugía , Vértebras Lumbares/cirugía , Fusión Vertebral/métodos , Adolescente , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Dolor de la Región Lumbar/etiología , Vértebras Lumbares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Satisfacción del Paciente , Periodo Posoperatorio , Estudios Prospectivos , Reoperación , Fusión Vertebral/efectos adversos , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Adulto Joven
8.
Anaesthesist ; 64(2): 137-44, 2015 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-25519190

RESUMEN

Specific communication training is currently not integrated into anesthesiology curricula. At the same time communication is an important key factor when working with colleagues, in the physician-patient relationship, during management of emergencies and in avoiding or reducing the legal consequences of adverse medical events. Therefore, focused attention should be brought to this area. In other high risk industries, specific communication training has been standard for a long time and in medicine there is an approach to teach and train these soft skills by simulation. Systematic communication training, however, is rarely an established component of specialist training. It is impossible not to communicate whereby nonverbal indications, such as gestures, mimic expression, posture and tone play an important part. Miscommunication, however, is common and leads to unproductive behavior. The cause of this is not always obvious. This article provides an overview of the communication models of Shannon, Watzlawick et al. and Schulz von Thun et al. and describes their limitations. The "Process Communication Model®" (PCM) is also introduced. An overview is provided with examples of how this tool can be used to look at the communication process from a systematic point of view. People have different psychological needs. Not taking care of these needs will result in individual stress behavior, which can be graded into first, second and third degrees of severity (driver behavior, mask behavior and desperation). These behavior patterns become exposed in predictable sequences. Furthermore, on the basis of this model, successful communication can be established while unproductive behavior that occurs during stress can be dealt with appropriately. Because of the importance of communication in all areas of medical care, opportunities exist to focus research on the influence of targeted communication on patient outcome, complications and management of emergencies.


Asunto(s)
Comunicación , Atención a la Salud/organización & administración , Anestesia , Competencia Clínica , Servicios Médicos de Urgencia , Humanos , Errores Médicos/prevención & control , Modelos Organizacionales , Relaciones Médico-Paciente
9.
Phys Rev Lett ; 113(22): 221101, 2014 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-25494064

RESUMEN

We report the first direct measurement of the overall characteristics of microwave radio emission from extensive air showers. Using a trigger provided by the KASCADE-Grande air shower array, the signals of the microwave antennas of the Cosmic-Ray Observation via Microwave Emission experiment have been read out and searched for signatures of radio emission by high-energy air showers in the GHz frequency range. Microwave signals have been detected for more than 30 showers with energies above 3×10^{16} eV. The observations presented in this Letter are consistent with a mainly forward-directed and polarized emission process in the GHz frequency range. The measurements show that microwave radiation offers a new means of studying air showers at E≥10^{17} eV.

10.
Phys Rev A (Coll Park) ; 109(2)2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38617901

RESUMEN

Ghost Imaging enables 2D reconstruction of an object even though particles transmitted or emitted by the object of interest are detected with a single pixel detector without spatial resolution. This is possible because for the particular implementation of ghost imaging presented here, the incident beam is spatially modulated with a non-configurable attenuating mask whose orientation is varied (e.g. via transverse displacement or rotation) in the course of the ghost imaging experiment. Each orientation yields a distinct spatial pattern in the attenuated beam. In many cases, ghost imaging reconstructions can be dramatically improved by factoring the measurement matrix which consists of measured attenuated incident radiation for each of many orientations of the mask at each pixel to be reconstructed as the product of an orthonormal matrix Qand an upper triangular matrix R provided that the number of orientations of the mask (N) is greater than or equal to the number of pixels (P) reconstructed. For the N

11.
Artículo en Inglés | MEDLINE | ID: mdl-38397662

RESUMEN

The coronavirus pandemic has generated and continues to create unprecedented demands on our healthcare systems. Healthcare workers (HCWs) face physical and psychological stresses caring for critically ill patients, including experiencing anxiety, depression, and posttraumatic stress symptoms. Nurses and nursing staff disproportionately experienced COVID-19-related psychological distress due to their vital role in infection mitigation and direct patient care. Therefore, there is a critical need to understand the short- and long-term impact of COVID-19 stress exposures on nursing staff wellbeing and to assess the impact of wellbeing programs aimed at supporting HCWs. To that end, the current study aims to evaluate an evidence-informed peer support stress reduction model, Stress First Aid (SFA), implemented across units within a psychiatric hospital in the New York City area during the pandemic. To examine the effectiveness of SFA, we measured stress, burnout, coping self-efficacy, resilience, and workplace support through self-report surveys completed by nurses and nursing staff over twelve months. The implementation of SFA across units has the potential to provide the workplace-level and individual-level skills necessary to reduce stress and promote resilience, which can be utilized and applied during waves of respiratory illness acuity or any other healthcare-related stressors among this population.


Asunto(s)
Agotamiento Profesional , COVID-19 , Personal de Enfermería , Humanos , COVID-19/epidemiología , Primeros Auxilios , Personal de Salud/psicología , Agotamiento Profesional/epidemiología
13.
J Radioanal Nucl Chem ; 332(8): 3285-3291, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37545764

RESUMEN

Three-dimensional printing and casting materials were analyzed by prompt gamma-ray activation analysis (PGAA) to determine their suitability as human tissue surrogates for the fabrication of phantoms for medical imaging and radiation dosimetry applications. Measured elemental compositions and densities of five surrogate materials simulating soft tissue and bone were used to determine radiological properties (x-ray mass attenuation coefficient and electron stopping power). When compared with radiological properties of International Commission on Radiation Units and Measurements (ICRU) materials, it was determined that urethane rubber and PLA plastic yielded the best match for soft tissue, while silicone rubber and urethane resin best simulated the properties of bone.

15.
Front Psychiatry ; 13: 1055495, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36569611

RESUMEN

Introduction: During the COVID-19 pandemic, physicians encountered significant COVID-19-related negative experiences and psychological distress in both their personal and professional lives. To understand the factors that negatively impact physician well-being, a number of studies have pointed to multiple work system factors such as excessive workload and workflow interruptions. In addition, studies have shown that positive interpersonal relationships that provide social support may also serve as a buffering role against psychological distress. The aim of our study explores the challenges and sources of support for physicians relative to mental health symptoms. Methods: In this study, We used a cross-sectional study design with a convergent parallel mixed method approach combining both qualitative and quantitative data collected in parallel from a self-report questionnaire immediately following the first wave of COVID-19. The aim of our study explores the challenges and sources of support for physicians relative to mental health symptoms. Results: Of the 457 physicians in the study, the most frequently potential negative occupational experiences were, "Being at risk of contracting COVID-19 from patients/co-workers" (90.5%) and "Contact with distressed family members who cannot be with a loved one" (69.5%). We identified five common themes for main sources of social support (e.g. emotional support from family/friends) and six themes for challenges (e.g., work-related demands exacerbated by the pandemic). Discussion: Our study highlights COVID-19 and other pandemic-related challenges that negatively impacted the mental health of physicians. Interventions that provide targeted organizational supports (e.g. sufficient PPE and child support), as well as specific sources of support (e.g. family and emotional), can attenuate those challenges and stressors experienced during a pandemic.

16.
Phys Rev Lett ; 107(17): 171104, 2011 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-22107501

RESUMEN

We report the observation of a steepening in the cosmic ray energy spectrum of heavy primary particles at about 8×10(16) eV. This structure is also seen in the all-particle energy spectrum, but is less significant. Whereas the "knee" of the cosmic ray spectrum at 3-5×10(15) eV was assigned to light primary masses by the KASCADE experiment, the new structure found by the KASCADE-Grande experiment is caused by heavy primaries. The result is obtained by independent measurements of the charged particle and muon components of the secondary particles of extensive air showers in the primary energy range of 10(16) to 10(18) eV. The data are analyzed on a single-event basis taking into account also the correlation of the two observables.

17.
HIV Clin Trials ; 12(1): 24-36, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21388938

RESUMEN

PURPOSE: We investigated the effects of maraviroc, the first approved CC-chemokine receptor 5 (CCR5) antagonist, on blood lipids in a post hoc analysis of the phase 3 MERIT study in treatment-naïve patients. METHODS: Patients received maraviroc 300 mg twice daily (n = 360) or efavirenz 600 mg once daily (n = 361), both in combination with zidovudine/lamivudine, for up to 96 weeks. Baseline and on- treatment lipid profiles were analyzed according to National Cholesterol Education Program (NCEP) thresholds. RESULTS: Baseline characteristics and lipid profiles were comparable between groups. Among patients with total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) below NCEP treatment thresholds at baseline, significantly more efavirenz- than maraviroc-treated patients exceeded those thresholds at 96 weeks (TC: 35% [74/209] vs 11% [20/188], P < .0001; LDL-c: 23% [47/197] vs 8% [15/183], P < .0001). Among patients exceeding NCEP thresholds at baseline, significantly more efavirenz- than maraviroc-treated patients exceeded the thresholds at 96 weeks (TC: 83% [24/29] vs 50% [17/34], P = .0084; LDL-c: 86% [19/22] vs 55% [16/29], P = .0314). Of those with baseline high- density lipoprotein cholesterol (HDL-c) < 40 mg/dL, 43% (56/130) of maravirocand 62% (86/139) of efavirenz-treated patients achieved HDL-c≥40 mg/dL at 96 weeks (P = .0020). CONCLUSIONS: Maraviroc was not associated with elevations in TC, LDL-c, or triglycerides and showed beneficial effects on lipid profiles of dyslipidemic patients.


Asunto(s)
Fármacos Anti-VIH/administración & dosificación , Benzoxazinas/administración & dosificación , Ciclohexanos/administración & dosificación , Dislipidemias/tratamiento farmacológico , Dislipidemias/virología , Infecciones por VIH/sangre , VIH-1/aislamiento & purificación , Triazoles/administración & dosificación , Adulto , Alquinos , Antagonistas de los Receptores CCR5 , Distribución de Chi-Cuadrado , Colesterol/sangre , Ciclopropanos , Dislipidemias/sangre , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Maraviroc , Receptores CCR5/metabolismo , Triglicéridos/sangre
18.
Nature ; 435(7040): 313-6, 2005 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-15902250

RESUMEN

The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

19.
J Dairy Sci ; 94(6): 3014-24, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21605771

RESUMEN

High feed costs are major obstacles for resource-poor dairy sheep farmers in West Asia, along with large fluctuation in grain and straw prices. Farmers need low-cost diets using locally available feeds that can provide sufficient milk of good quality. Two experimental trials were conducted on Awassi milking ewes to evaluate nonconventional and balanced low-cost diets against the traditional unbalanced diet used by farmers (control) on the total yields (milk, fat, protein, and total solids) and milk composition (fat, protein, total solids, and lactose), an important indicator of milk quality. The first trial was conducted at the research station of the International Center for Agricultural Research in the Dry Areas (ICARDA, Aleppo, Syria) to test 6 low-cost balanced diets using locally available feeds and agro byproducts against the control diet. Each diet was tested on 8 ewes that were kept on pasture as a basal diet, but received different supplements, including barley, wheat bran and nonconventional feeds (urea-treated wheat straw, molasses, sugar beet pulp, and cotton seed cake). Five balanced diets enhanced the total yields of milk, fat, protein, and total solids, in 2 cases, significantly. These diets increased total milk yield by 17.7 to 50.2% and decreased supplement feeding costs by 43% compared with the control. However, milk composition remained unaffected. The second trial was conducted on 3 different farms in northern Syria to assess in each farm a low-cost balanced diet on milking ewes (n=15) in comparison to the farmer's control (n=15). The balanced diet was a modification requested by farmers of the best performing diet in the on-station trial. Confirming the first trial's research results, the balanced diet outperformed the control in total yields; for instance, it increased total milk yield by 28 to 40% and raised net income by 30%, without affecting milk composition. Both trials showed that using locally available nonconventional feedstuffs, such as molasses, integrated into balanced dairy sheep diets can decrease feed costs of resource-poor farmers, while enhancing total yields of milk and milk constituents without compromising milk quality components. This will greatly improve the profitability of dairy sheep production in dry areas.


Asunto(s)
Alimentación Animal/economía , Industria Lechera/métodos , Dieta/veterinaria , Lactancia/fisiología , Leche/química , Ovinos/fisiología , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Industria Lechera/economía , Dieta/economía , Grasas de la Dieta/análisis , Femenino , Lactosa/análisis , Leche/metabolismo , Proteínas de la Leche/análisis , Siria
20.
J Dairy Sci ; 94(12): 5737-49, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22118064

RESUMEN

Increased feed costs affect the livelihoods of dairy sheep farmers in the Middle East. Farmers endure high risks with large fluctuations in the price of grain used as animal feed, which is further affected by drought and declining range productivity. Using agricultural by-products and treated straw or vetch grazing for supplementing sheep diets would provide resource-poor dairy farmers with increased options to reduce feed costs, but the effects of such feeds on the quality of yogurt (the main product) need to be better understood. Two experiments were conducted to evaluate these effects. The first trial evaluated alternative diets using locally available feedstuffs, including agricultural by-products, compared with traditional diets used by dairy sheep farmers, and was conducted on-station at the International Center for Agricultural Research in Dry Areas (ICARDA, Tel Hadya, Aleppo, Syria). Milking Awassi ewes (n=56) were used to test 6 alternative diets against a traditional control diet containing barley, wheat bran, and barley straw. The 6 alternative diets contained 4 or more of the following ingredients: barley, sugar beet pulp, molasses, cotton seed cake, wheat bran, urea-treated wheat straw, and barley straw. Ewes on one of the alternative diets grazed vetch pasture, whereas ewes on the control diet and the 5 alternative diets grazed native range pasture. The milk fat content was higher in diets containing urea-treated straw. Yogurt firmness and adhesiveness were significantly lower in energy-rich diets (e.g., the control diet) and in the diets rich in soluble sugar (molasses). The effects of diet on yogurt color and on citric and succinic acid contents were significant. A yogurt produced from the milk of the group grazing on vetch was the most yellowish in color, which is appealing to Syrian consumers. The content of citric acid tended to be higher in yogurts produced from diets containing molasses. The second trial was conducted on 3 farms in northern Syria to assess an alternative diet (1 of the 6 tested in the first trial) on 15 milking ewes compared with the farmer's traditional diet (control). The alternative diet increased yogurt firmness and adhesiveness by 7 to 9% and 10 to 16%, respectively. The use of nonconventional feeds available in the region enhances yogurt quality, may reduce requirements for expensive grains, and thus, increase farmers' livelihoods by targeting expanding markets with better quality products.


Asunto(s)
Alimentación Animal , Suplementos Dietéticos , Leche/normas , Ovinos/metabolismo , Yogur/normas , Animales , Industria Lechera/métodos , Grasas/análisis , Femenino , Lactosa/análisis , Medio Oriente , Leche/química , Proteínas de la Leche/análisis , Yogur/análisis
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