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1.
Occup Med (Lond) ; 73(2): 80-84, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36719096

RESUMO

BACKGROUND: Attrition from combat service carries significant organizational and personal ramifications, but predicting factors associated with attrition remains challenging. AIMS: To evaluate medical and psychosocial factors associated with attrition from basic combat training (BCT) in the Israel Defense Forces (IDF). In addition, we identify subsets of the recruit population which exhibit certain trends in terms of medical corresponding with a high risk of attrition. METHODS: A cross-sectional study of IDF combat trainees undergoing infantry BCT between 2012 and 2017. Data were collected from the soldiers' electronic medical and administrative records. We used multivariable logistic regression and the SAS® decision-tree tool to analyse key predictive factors for attrition. RESULTS: A total of 46 472 soldiers enlisted to BCT during the research period. The mean body mass index (BMI) was 21.8 (SD 3.54). The overall attrition rate was 10%. The following factors were associated with attrition from BCT: ethnicity (P < 0.01), BMI (P < 0.01), pre-enlisting motivation score (P < 0.01) and the number of mental health officer visits (P < 0.01). Using a decision-tree model, we found a high attrition rate among soldiers who had >5.2 to primary care physician visits (11% attrition rate versus 3%) or more than 11 sick leave days (59% versus 19%). CONCLUSIONS: This study sheds light on unique measures relating to attrition. Attrition is associated with several demographic and psychosocial factors. Early prediction of motivation and monitoring of healthcare utilization may enable early identification and focused interventions targeting soldiers at high risk for attrition. These findings need to be further translated into actionable directives and further investigations.


Assuntos
Militares , Humanos , Militares/psicologia , Israel/epidemiologia , Estudos Transversais , Saúde Mental
2.
J Dairy Sci ; 104(3): 2807-2821, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33455793

RESUMO

There has been a global push for improved antimicrobial stewardship, including in animal agriculture, due to growing concerns about antimicrobial resistance. However, little is known about the general public's perceptions of antimicrobial use in animal agriculture. The aim of this study was to explore the US public's perceptions of antibiotic use in dairy farming and how these perceptions influence purchasing decisions. Data from the 2017 Cornell National Social Survey developed in collaboration with the Cornell Survey Research Institute were used to assess the public's perceptions. The Survey Research Institute of Cornell University (Ithaca, NY) administered the survey by telephone to a random sample of 1,000 adults in the continental United States. The survey collected information about perceptions of threat to human health posed by antibiotic use in cows on dairy farms and willingness to pay more for milk from cows raised without antibiotics, as well as several presumed explanatory variables, including respondents' knowledge of antibiotics, beliefs regarding cattle treatment in dairy farming, and 18 sociodemographic characteristics. Data were analyzed using logistic regression. Among respondents, 90.7% (n = 892/983) reported that antibiotic use on dairy farms posed some level of threat to human health and 71.5% (n = 580/811) indicated they would be willing to pay more for milk produced from cows raised without antibiotics. Respondents who believed that antibiotic use in dairy farming posed a moderate to high threat to human health were more likely to be female and report willingness to pay more for milk or not purchase milk. Additionally, consumers' willingness to pay more for milk from cattle raised without antibiotics was associated with the belief that antibiotic use posed some threat to human health, the belief that cows are treated better on organic dairy farms, an annual household income of $50,000 or greater, being born outside the United States, having a liberal social ideology, and being currently or formerly married. These results suggest that the general public's decisions as consumers of dairy products are associated with demographic factors in addition to perceptions of antibiotic use and cattle treatment in dairy farming. The rationale behind such perceptions should be further explored to facilitate consumers' informed decision making about antibiotic use in agriculture, links to cattle treatment, and associated willingness-to-pay attitudes.


Assuntos
Antibacterianos , Indústria de Laticínios , Animais , Bovinos , Fazendas , Feminino , Leite , Opinião Pública , Estados Unidos
3.
Phys Rev Lett ; 123(17): 175001, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31702277

RESUMO

We report experimental measurements of the threshold for multipactor discharges on dielectric surfaces at 110 GHz. Multipactor was studied in two geometries: electric field polarized parallel to or perpendicular to the sample surface. Measured multipactor thresholds ranged from 15 to 34 MV/m, more than 10 times higher than those found at conventional microwave frequencies. Measured thresholds were compared with prior data at lower frequencies, showing agreement with theoretical predictions that thresholds increase linearly with frequency. Measurements of the rf power dissipated in the multipactor show low dissipation (≤1%) for the parallel electric field case, but very strong dissipation for the perpendicular case, also in agreement with theoretical predictions. The agreement between experiment and theory over a wide range of frequencies provides a strong basis for the understanding of dielectric multipactor discharges.

4.
Phys Rev Lett ; 123(24): 244801, 2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31922865

RESUMO

This Letter reports the successful experimental demonstration of amplification of subterahertz radiation in a klystron with photonic crystal cavities. The klystron has six cavities, with each cavity having a series of oversized photonic crystal cells made up of a 5×3 array of square posts. The center post is removed from each cell to form a highly oversized (0.8 mm∼λ/4) beam tunnel, with power coupling from cell to cell through the tunnel. The pulsed electron beam is operated at 23.5 kV, 330 mA in a 0.5 T solenoidal field. At 93.7 GHz, a small-signal gain of 26 dB and a saturated output power of 30 W are obtained. Experimental results are in very good agreement with the predictions of a particle-in-cell code. The successful achievement of high gain operation of a photonic crystal klystron amplifier is promising for the future extension of klystron operation well into the terahertz frequency region.

5.
Climacteric ; 22(1): 38-43, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30452294

RESUMO

Genitourinary syndrome of menopause including vulvovaginal atrophy is commonly experienced by postmenopausal women, reducing their quality of life. The aim of this review is to assess current treatment options within the framework of recent management guidelines. Recommendations include use of treatments addressing both symptoms and the underlying pathophysiology, and proactive patient discussion. Both prescription and non-prescription options are recognized, including non-hormone-based approaches. Local therapy is preferable in the primary treatment of genitourinary syndrome of menopause symptoms as risk of adverse events is reduced, although long-term safety data are limited. Management of patients with a history of breast cancer requires careful consideration, although estrogen therapy has not been associated with increased risk of breast cancer or of recurrence. Treatment should consider ongoing cancer therapy. As multiple, comparable options exist, treatment choice may be due to experience and patient preference. Best management requires effective patient-physician communication and shared decision-making.


Assuntos
Terapia de Reposição de Estrogênios/métodos , Menopausa , Qualidade de Vida , Vagina/patologia , Administração Intravaginal , Atrofia/tratamento farmacológico , Neoplasias da Mama/epidemiologia , Tomada de Decisão Compartilhada , Dispareunia/tratamento farmacológico , Terapia de Reposição de Estrogênios/efeitos adversos , Feminino , Humanos , Relações Médico-Paciente , Cremes, Espumas e Géis Vaginais/uso terapêutico , Saúde da Mulher
6.
Prikl Biokhim Mikrobiol ; 53(2): 173-87, 2017.
Artigo em Russo | MEDLINE | ID: mdl-29508978

RESUMO

Contaminating proteins have been identified by "shotgun" proteomic analysis in 14 recombinant preparations of human membrane heme- and flavoproteins expressed in Escherichia coli and purified by immobilized metal ion affinity chromatography. Immobilized metal ion affinity chromatography of ten proteins was performed on Ni2+-NTA-sepharose 6B, and the remaining four proteins were purified by ligand affinity chromatography on 2',5'-ADP-sepharose 4B. Proteomic analysis allowed to detect 50 protein impurities from E. coli. The most common contaminant was Elongation factor Tu2. It is characterized by a large dipole moment and a cluster arrangement of acidic amino acid residues that mediate the specific interaction with the sorbent. Peptidyl prolyl-cis-trans isomerase SlyD, glutamine-fructose-6-phosphate aminotransferase, and catalase HPII that contained repeating HxH, QxQ, and RxR fragments capable of specific interaction with the sorbent were identified among the protein contaminants as well. GroL/GroS chaperonins were probably copurified due to the formation of complexes with the target proteins. The Ni2+ cations leakage from the sorbent during lead to formation of free carboxyl groups that is the reason of cation exchanger properties of the sorbent. This was the putative reason for the copurification of basic proteins, such as the ribosomal proteins of E. coli and the widely occurring uncharacterized protein YqjD. The results of the analysis revealed variation in the contaminant composition related to the type of protein expressed. This is probably related to the reaction of E. coli cell proteome to the expression of a foreign protein. We concluded that the nature of the protein contaminants in a preparation of a recombinant protein purified by immobilized metal ion affinity chromatography on a certain sorbent could be predicted if information on the host cell proteome were available.


Assuntos
Cromatografia de Afinidade/métodos , Proteínas de Escherichia coli/isolamento & purificação , Flavoproteínas/isolamento & purificação , Hemeproteínas/isolamento & purificação , Proteômica/métodos , Sequência de Aminoácidos , Catalase/isolamento & purificação , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Flavoproteínas/genética , Flavoproteínas/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/isolamento & purificação , Proteínas de Choque Térmico/isolamento & purificação , Hemeproteínas/genética , Hemeproteínas/metabolismo , Humanos , Fator Tu de Elongação de Peptídeos/isolamento & purificação , Peptidilprolil Isomerase/isolamento & purificação , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Ribossômicas/isolamento & purificação , Sefarose/análogos & derivados , Sefarose/química
7.
Phys Rev Lett ; 117(23): 237701, 2016 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-27982613

RESUMO

An electron beam passing through a metamaterial structure is predicted to generate reversed Cherenkov radiation, an unusual and potentially very useful property. We present an experimental test of this phenomenon using an intense electron beam passing through a metamaterial loaded waveguide. Power levels of up to 5 MW are observed in backward wave modes at a frequency of 2.40 GHz using a one microsecond pulsed electron beam of 490 keV, 84 A in a 400 G magnetic field. Contrary to expectations, the output power is not generated in the Cherenkov mode. Instead, the presence of the magnetic field, which is required to transport the electron beam, induces a Cherenkov-cyclotron (or anomalous Doppler) instability at a frequency equal to the Cherenkov frequency minus the cyclotron frequency. Nonlinear simulations indicate that the Cherenkov-cyclotron mode should dominate over the Cherenkov instability at a lower magnetic field where the highest output power is obtained.

8.
Epidemiol Infect ; 144(8): 1748-55, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27125574

RESUMO

Vancomycin-resistant enterococci (VRE) infections are a public health threat associated with increased patient mortality and healthcare costs. Antibiotic usage, particularly cephalosporins, has been associated with VRE colonization and VRE bloodstream infections (VRE BSI). We examined the relationship between antimicrobial usage and incident VRE colonization at the individual patient level. Prospective, weekly surveillance was undertaken for incident VRE colonization defined by negative admission but positive surveillance swab in a medical intensive care unit over a 17-month period. Antimicrobial exposure was quantified as days of therapy (DOT)/1000 patient-days. Multiple logistic regression was used to analyse incident VRE colonization and antibiotic DOT, controlling for demographic and clinical covariates. Ninety-six percent (1398/1454) of admissions were swabbed within 24 h of intensive care unit (ICU) arrival and of the 380 patients in the ICU long enough for weekly surveillance, 83 (22%) developed incident VRE colonization. Incident colonization was associated in bivariate analysis with male gender, more previous hospital admissions, longer previous hospital stay, and use of cefepime/ceftazidime, fluconazole, azithromycin, and metronidazole (P < 0·05). After controlling for demographic and clinical covariates, metronidazole was the only antibiotic independently associated with incident VRE colonization (odds ratio 2·0, 95% confidence interval 1·2-3·3, P < 0·009). Our findings suggest that risk of incident VRE colonization differs between individual antibiotic agents and support the possibility that antimicrobial stewardship may impact VRE colonization and infection.


Assuntos
Antibacterianos/uso terapêutico , Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Uso de Medicamentos , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Enterococos Resistentes à Vancomicina/isolamento & purificação , Adulto , Idoso , Monitoramento Epidemiológico , Feminino , Humanos , Incidência , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
9.
Acta Neurochir (Wien) ; 157(7): 1125-9; discussion 1130, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25981434

RESUMO

BACKGROUND: The use of minimally porous endoluminal devices (MPEDs) such as the Pipeline Embolization Device (PED) has been described for the treatment of brain aneurysms. The benefit of using MPEDs to assist embolization of a direct high-flow carotid cavernous fistula resulting from a ruptured cavernous carotid artery aneurysm is not well documented. METHODS: We describe our experience with deploying a tailored multidevice PED construct across the cavernous internal carotid artery (ICA) wall defect in combination with transarterial coil embolization using the "jailed microcatheter" technique. RESULTS: A 59-year-old woman presented with acute left-sided ophthalmoplegia. Diagnostic cerebral angiography demonstrated a ruptured giant cavernous carotid aneurysm with fistulous outflow via the ipsilateral left superior ophthalmic vein and into the pterygoid venous plexi bilaterally. Via the Marksman microcatheter, a total of three PEDs measuring 4.5 mm × 18 mm, 4.5 mm × 20 mm, and 4.75 mm × 16 mm were telescoped within the ICA across the aneurysm neck. Coiling of the aneurysm fundus and cavernous sinus via the "jailed" Rapidtransit microcatheter was subsequently achieved. A 2-year follow-up digital subtraction angiography (DSA) demonstrated stable obliteration of the aneurysm and the fistula, coincident with complete resolution of the patient's symptoms. CONCLUSIONS: Based on our long-term clinical and angiographic results, we advocate that the presented method be a valid treatment option for selected cases.


Assuntos
Prótese Vascular , Fístula Carótido-Cavernosa/cirurgia , Embolização Terapêutica/métodos , Dispositivos de Acesso Vascular , Aneurisma Roto/complicações , Aneurisma Roto/cirurgia , Fístula Carótido-Cavernosa/etiologia , Embolização Terapêutica/instrumentação , Feminino , Humanos , Pessoa de Meia-Idade
10.
Thorac Cardiovasc Surg ; 62(3): 255-7; discussion 257, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23344756

RESUMO

This is a case report on a 26-year-old woman with metastatic mandibular osteosarcoma to the lung. A video-assisted thorascopic surgery (VATS) completion left upper lobe lobectomy was attempted, but was converted to a thoracotomy when anomalous pulmonary vein drainage (APVD) was identified. There were no other anomalies found and the lobectomy was completed as planned. To our knowledge, this is the first reported case of an attempted VATS lobectomy for patients with APVD. This case demonstrates that APVD tends not to be associated with any other anatomic abnormalities in the lung and should not be a contraindication for VATS lobectomy.


Assuntos
Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Neoplasias Mandibulares/patologia , Osteossarcoma/secundário , Osteossarcoma/cirurgia , Pneumonectomia/métodos , Veias Pulmonares/anormalidades , Cirurgia Torácica Vídeoassistida , Adulto , Feminino , Humanos , Veias Pulmonares/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Resultado do Tratamento
11.
Phys Rev Lett ; 111(23): 235101, 2013 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-24476286

RESUMO

We report the experimental demonstration of a gyrotron traveling-wave-tube amplifier at 250 GHz that uses a photonic band gap (PBG) interaction circuit. The gyrotron amplifier achieved a peak small signal gain of 38 dB and 45 W output power at 247.7 GHz with an instantaneous -3 dB bandwidth of 0.4 GHz. The amplifier can be tuned for operation from 245-256 GHz. The widest instantaneous -3 dB bandwidth of 4.5 GHz centered at 253.25 GHz was observed with a gain of 24 dB. The PBG circuit provides stability from oscillations by supporting the propagation of transverse electric (TE) modes in a narrow range of frequencies, allowing for the confinement of the operating TE03-like mode while rejecting the excitation of oscillations at nearby frequencies. This experiment achieved the highest frequency of operation for a gyrotron amplifier; at present, there are no other amplifiers in this frequency range that are capable of producing either high gain or high output power. This result represents the highest gain observed above 94 GHz and the highest output power achieved above 140 GHz by any conventional-voltage vacuum electron device based amplifier.


Assuntos
Ciclotrons/instrumentação , Modelos Teóricos , Óptica e Fotônica/instrumentação , Óptica e Fotônica/métodos
12.
AJNR Am J Neuroradiol ; 44(8): 934-938, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37414456

RESUMO

BACKGROUND: Transophthalmic artery embolization of intracranial meningiomas is thought to be associated with a high complication risk. PURPOSE: With advances in endovascular techniques, we systematically reviewed the current literature to improve our understanding of the safety and efficacy of transophthalmic artery embolization of intracranial meningiomas. DATA SOURCES: We performed a systematic search using PubMed from inception until August 3, 2022. STUDY SELECTION: Twelve studies with 28 patients with intracranial meningiomas embolized through the transophthalmic artery were included. DATA ANALYSIS: Baseline and technical characteristics and clinical and safety outcomes were collected. No statistical analysis was conducted. DATA SYNTHESIS: The average age of 27 patients was 49.5 (SD, 13) years. Eighteen (69%) meningiomas were located in the anterior cranial fossa, and 8 (31%), in the sphenoid ridge/wing. Polyvinyl alcohol particles were most commonly (n = 8, 31%) used to preoperatively embolize meningiomas, followed by n-BCA in 6 (23%), Onyx in 6 (23%), Gelfoam in 5 (19%), and coils in 1 patient (4%). Complete embolization of the target meningioma feeders was reported in 8 (47%) of 17 patients; partial embolization, in 6 (32%); and suboptimal embolization, in 3 (18%). The endovascular complication rate was 16% (4 of 25), which included visual impairment in 3 (12%) patients. LIMITATIONS: Selection and publication biases were limitations. CONCLUSIONS: Transophthalmic artery embolization of intracranial meningiomas is feasible but is associated with a non-negligible complication rate.


Assuntos
Embolização Terapêutica , Neoplasias Meníngeas , Meningioma , Humanos , Adulto , Meningioma/terapia , Neoplasias Meníngeas/terapia , Cuidados Pré-Operatórios/métodos , Embolização Terapêutica/métodos , Artérias , Resultado do Tratamento , Estudos Retrospectivos
13.
Dis Esophagus ; 25(8): 702-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22309285

RESUMO

Gastroesophageal reflux disease (GERD) causes a wide range of symptoms. Some patients present with typical symptoms such as heartburn and regurgitation and others with atypical symptoms such as chest pain. The mechanism responsible for the varying clinical presentation of GERD is still not fully elucidated. The aim of this study was to prospectively evaluate differences in central and local intraesophageal factors between patients with typical GERD symptoms and those with noncardiac chest pain (NCCP). Patients presenting with typical and atypical symptoms suspicious of GERD underwent upper endoscopy and 24-hour pH monitoring with four sensors, each positioned at a different esophageal level. All patients completed GERD symptom, Hospital Anxiety and Depression Scale, and Symptom Stress Rating questionnaires. From January 2006 to December 2009, 50 patients were recruited, 29 with typical symptoms, and 21 with NCCP. Patients with proven GERD and NCCP had higher proximal extension of acid during reflux episodes than patients with typical symptoms. They were found to be older, had a shorter history of symptom onset, worse anxiety scores, and more endoscopic findings compatible with gastritis. Proximal extension of acid during the reflux episodes in patients with GERD presenting with NCCP may play a role in symptom generation.


Assuntos
Ansiedade/complicações , Dor no Peito/etiologia , Refluxo Gastroesofágico/patologia , Refluxo Gastroesofágico/fisiopatologia , Adulto , Fatores Etários , Distribuição de Qui-Quadrado , Monitoramento do pH Esofágico , Esofagoscopia , Feminino , Gastrite/complicações , Gastrite/patologia , Refluxo Gastroesofágico/complicações , Azia/etiologia , Humanos , Refluxo Laringofaríngeo/etiologia , Masculino , Pessoa de Meia-Idade , Postura , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Estatísticas não Paramétricas , Inquéritos e Questionários , Fatores de Tempo , Adulto Jovem
14.
AJNR Am J Neuroradiol ; 43(8): 1142-1147, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35902121

RESUMO

BACKGROUND AND PURPOSE: Skull base tumors are commonly supplied by dural branches of the meningohypophyseal and inferolateral trunks. Embolization through these arteries is often avoided due to technical challenges and inherent risks; however, successful embolization can be a valuable surgical adjunct. We aimed to review the success and complications in our series of tumor embolizations through the meningohypophyseal and inferolateral trunks. MATERIALS AND METHODS: We performed a retrospective review of patients with tumor treated with preoperative embolization at our institution between 2010 and 2020. We reviewed the following data: patients' demographics, tumor characteristics, endovascular embolization variables, and surgical results including estimated blood loss, the need for transfusion, and operative time. RESULTS: Among 155 tumor embolization cases, we identified 14 patients in whom tumor embolization was performed using the meningohypophyseal (n = 13) or inferolateral (n = 4) trunk. In this group of patients, on average, 79% of tumors were embolized. No mortality or morbidity from the embolization procedure was observed in this subgroup of patients. The average estimated blood loss in the operation was 395 mL (range, 200-750 mL). None of the patients required a transfusion, and the average operative time was 7.3 hours. CONCLUSIONS: Some skull base tumors necessitate embolization through ICA branches such as the meningohypophyseal and inferolateral trunks. Our series demonstrates that an effective and safe embolization may be performed through these routes.


Assuntos
Embolização Terapêutica , Neoplasias da Base do Crânio , Humanos , Artérias , Embolização Terapêutica/métodos , Cuidados Pré-Operatórios/métodos , Estudos Retrospectivos , Neoplasias da Base do Crânio/diagnóstico por imagem , Neoplasias da Base do Crânio/terapia
15.
Am J Transplant ; 11(3): 426-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21342444

RESUMO

Internationally accepted ethical standards are unequivocal in their prohibition of the use of organs recovered from executed prisoners: yet this practice continues in China despite indications that Ministry of Health officials intend to end this abhorrent practice. Recently published articles on this topic emphasize the medical complications that result from liver transplantation from executed 'donors' but scant attention is given to the source of the organs, raising concern that the transplant community may be becoming inured to unacceptable practice. Strategies to influence positive change in organ donation practice in China by the international transplant community are discussed. They include an absolutist policy whereby no clinical data from China is deemed acceptable until unacceptable donation practices end, and an incremental policy whereby clinical data is carefully evaluated for acceptability. The relative advantages and drawbacks of these strategies are discussed together with some practical suggestions for response available to individuals and the transplant community.


Assuntos
Doadores Vivos/estatística & dados numéricos , Transplante de Órgãos/ética , Prisioneiros/legislação & jurisprudência , Obtenção de Tecidos e Órgãos/ética , China , Humanos
16.
J Chem Phys ; 135(19): 194310, 2011 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-22112085

RESUMO

The effects of laser-induced pre-alignment on the deflection of paramagnetic molecules by inhomogeneous static magnetic field are studied. Depending on the relevant Hund's coupling case of the molecule, two different effects were identified: either suppression of the deflection by laser pulses (Hund's coupling case (a) molecules, such as ClO), or a dramatic reconstruction of the broad distribution of the scattering angles into several narrow peaks (for Hund's coupling case (b) molecules, such as O(2) or NH). These findings are important for various applications using molecular guiding, focusing and trapping with the help of magnetic fields.

17.
AJNR Am J Neuroradiol ; 42(7): 1282-1284, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33832953

RESUMO

DSA is the standard imaging technique for evaluation of cerebrovascular conditions. However, One drawback is its limitation in depicting a single angiographic phase at a time. We describe a new 3D-DSA algorithm, which we call arterial and venous-3D-DSA, which allows the concurrent yet distinct display of the arterial and venous structures, which may be useful for different clinical and educational purposes.


Assuntos
Imageamento Tridimensional , Neuroimagem , Algoritmos , Angiografia Digital , Artérias , Humanos
18.
19.
J Infrared Millim Terahertz Waves ; 42: 547-556, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34290840

RESUMO

The effect of reflection is studied experimentally and theoretically on a high-power 110 GHz gyrotron operating in the TE22,6 mode in 3 µs pulses at 96 kV, 40 A. The experimental setup allows variation of the reflected power from 0 to 33 % over a range of gyrotron operating conditions. The phase of the reflection is varied by translating the reflector along the axis. Operating at a higher efficiency point, at 4:40 T with 940 kW of output power, reflected power exceeding 11% causes a switch from operation in the TE22,6 to simultaneous operation in the TE22,6 and TE21,6 modes with a large decrease of the total gyrotron output power. This switching effect is in good agreement with simulations using the MAGY code. Operating at a more stable point, 4:44 T with 580 kW of output power, when the reflection is increased, the output power remains in the TE22,6 mode but it decreases monotonically with increasing reflection, dropping to 200 kW at 33% reflection. Furthermore, at a reflection above 22%, a power modulation at 25 to 30 MHz is observed, independent of the phase of the reflected wave. Such a modulated signal may be useful in spectroscopic and other applications.

20.
J Exp Med ; 153(1): 166-81, 1981 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-6161205

RESUMO

The immunochemical specificity of the combining sites of murine myeloma protein CAL20 TEPC1035 was studied by quantitative precipitin and precipitin inhibition assays. Myeloma protein CAL20 TEPC1035 precipitated with only three dextrans, B1355S4, B1498S, and B1501S, with high proportions of alpha(1 leads to 3) linkages, but not with any other dextrans, glycogen, and pullulan. Inhibition tests with various sugars show that the combining site of myeloma protein CAL20 TEPC1035 is most complementary to panose, a trisaccharide DGlc alpha(1 leads to 6)DGlc alpha(1 leads to 4)DGlc. Panose was 3.3 times more potent than a tetrasaccharide DGlc alpha(1 leads to 6)DGlc alpha(1 leads to 4)DGlc alpha(1 leads to 4)DGlc and 8, 23, 42, > 42 times more active than maltose, nigerose, isomaltose, and kojibiose, respectively. These findings were paralleled by their binding properties as determined by affinity electrophoresis. The association constants (Ka) of these three dextrans to myeloma protein CAL20 TEPC1035 ranged from 3.8 X 10(3) ml/g to 5.02 X 10(3) ml/g. The association constant of inhibitor (Kia) of panose was 8.19 X 10(3) M-1. Myeloma protein CAL20 TEPC1035 is an antidextran with specificity different from those of other murine myeloma antidextrans and from human antidextrans reported previously and its combining site size is at least as large as a trisaccharide. The binding constant of methyl alpha-D-glucoside (7.2 X 10(2)) was 73% of that of panose and comparable to that of myeloma protein W3129 (9.4 X 10(2)) with a cavity-type site and 600 times lower (1.6 X 10(0)) for QUPC52 with a groove type site, indicating that the terminal nonreducing residue is held in a cavity. Inhibition data with various alpha(1 leads to 4)-linked oligosaccharides also indicate that the internal portions of these inhibitors may react directly with a portion of the combining site. These findings suggest that myeloma antidextran CAL20 TEPC1035 has a partial cavity-type combining site in which the terminal nonreducing dGlc alpha(1 leads to 6) moiety is held in a cavity with the other two sugars forming a groove. However, oligosaccharides with one or more alternating [leads to 3DGlc alpha(1 leads to 6)DGlc alpha(1 leads to 3)DGlcl leads to] units with and without terminal nonreducing DGlc alpha(1 leads to 6) or DGLc alpha(1 leads to 3) side chains remain to be tested to determine whether structures known to be present in the three dextrans which precipitate CAL20 TEPC1035 may not prove to be more active than panose.


Assuntos
Sítios de Ligação de Anticorpos , Dextranos/imunologia , Proteínas do Mieloma/imunologia , Animais , Epitopos , Camundongos , Oligossacarídeos/imunologia , Testes de Precipitina , Relação Estrutura-Atividade
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