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1.
Analyst ; 147(5): 870-879, 2022 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-35136893

RESUMEN

Differential ion mobility (DMS) is a versatile ion separation method that is often integrated with mass spectrometry (MS). In DMS, extremely high electric fields are used such that ion mobility depends non-linearly on electric field and thus, ion separations can be more orthogonal to MS than lower field ion mobility-based methods. DMS can have sufficiently high resolution to be used for enantiomer analysis of small molecules and to separate protein ions with peak widths comparable to those obtained for peptides. However, the performance of high resolution DMS-MS can be limited owing to the substantial loss of ions (>10-fold) that can occur upon their transfer from atmospheric pressure (where DMS separation typically occurs) to vacuum through a narrow conductance limited inlet (e.g. capillary) to the MS. Here, results from simulated ion trajectory simulations suggest that in high resolution DMS most ions can be lost by 'crashing' onto the narrow capillary inlet after exiting the DMS separation channel. To enhance DMS sensitivity and resolving power, an integrated DMS-MS interface concept is reported that consists of a slit electrode and a 12-electrode atmospheric pressure ion funnel (APIF). By using an APIF with slit entrance, the simulated ion transmission efficiencies increase by up to 257% for singly charged ions ([DMMP + H]+, [tryptophan + H]+, and [(2-dodecanone)2 + H]+) and by 209% for [ubiquitin + 12H]12+, without compromising resolving power. The use of APIF improves the ion focussing from the DMS exit to the MS capillary to improve sensitivity, and the slit ensures that ion dispersion in the analytically relevant direction perpendicular to the DMS electrodes is restricted to enhance resolution. By narrowing the slit of the DMS-Slit-APIF interface, the DMS resolving power can be increased further by at least 20%. Overall, these results indicate that the integrated DMS-Slit-APIF interface is promising for improving the sensitivity and resolution for many different types of DMS-MS experiments.


Asunto(s)
Presión Atmosférica , Espectrometría de Movilidad Iónica , Iones , Espectrometría de Masas , Estereoisomerismo
2.
Chaos Solitons Fractals ; 155: 111636, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34866811

RESUMEN

Novel coronavirus named SARS-CoV-2 is one of the global threads and uncertain challenges worldwide faced at present. It has stroke rapidly around the globe due to viral transmissibility, new variants (strains), and human unconsciousness. Lack of adequate and reliable vaccination and proper treatment, control measures such as self-protection, physical distancing, lockdown, quarantine, and isolation policy plays an essential role in controlling and reducing the pandemic. Decisions on enforcing various control measures should be determined based on a theoretical framework and real-data evidence. We deliberate a general mathematical control measures epidemic model consisting of lockdown, self-protection, physical distancing, quarantine, and isolation compartments. Then, we investigate the proposed model through Caputo fractional order derivative. Fixed point theory has been used to analyze the Caputo fractional-order derivative model's existence and uniqueness solutions, whereas the Adams-Bashforth-Moulton numerical scheme was applied for numerical simulation. Driven by extensive theoretical analysis and numerical simulation, this work further illuminates the substantial impact of various control measures.

3.
J Theor Biol ; 509: 110531, 2021 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-33129951

RESUMEN

As protection against infectious disease, immunity is conferred by one of two main defense mechanisms, namely (i) resistance generated by previous infection (known as natural immunity) or (ii) by being vaccinated (known as artificial immunity). To analyze, a modified SVIRS epidemic model is established that integrates the effects of the durability of protection and imperfectness in the framework of the human decision-making process as a vaccination game. It is supposed that immunized people become susceptible again when their immunity expires, which depends on the duration of immunity. The current theory for most voluntary vaccination games assumes that seasonal diseases such as influenza are controlled by a temporal vaccine, the immunity of which lasts for only one season. Also, a novel perspective is established involving an individual's immune system combined with self-interest to take the vaccine and natural immunity obtained from infection by coupling a disease-spreading model with an evolutionary game approach over a long period. Numerical simulations show that the longer attenuation helps significantly to control the spread of disease. Also discovered is the entire mechanism of active and passive immunities, in the sense of how they coexist with natural and artificial immunity. Thus, the prospect of finding the optimal strategy for eradicating a disease could help in the design of effective vaccination campaigns and policies.


Asunto(s)
Vacunas contra la Influenza , Gripe Humana , Humanos , Inmunidad Innata , Programas de Inmunización , Gripe Humana/prevención & control , Vacunación
4.
Anal Chem ; 92(24): 15811-15817, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-33259206

RESUMEN

In mass spectrometry (MS), a major loss of ions can readily occur during their transfer from atmospheric pressure to a lower pressure, which limits performance. Here, we report an ion funnel that can be used to effectively focus ions at ambient pressure (∼777 Torr) to significantly enhance performance in electrospray ionization (ESI) MS. For seven singly charged test ions (m/z 124-1131), the ambient pressure ion funnel (APIF) is demonstrated to improve ion abundances, sensitivity, and detection limits by up to factors of ∼17, ∼16, and ∼3, respectively, compared to the operation of conventional ESI-MS. Simulated ion trajectories were used to rationalize the enhanced performance of the APIF, which is attributed primarily to using a relatively high RF field amplitude to radially confine ions, a high DC field, and a wide exit ring electrode. The effective focusing of ions at ambient pressures should be beneficial in the future for improving the performance of (i) additional methods that ionize molecules at atmospheric pressure, (ii) ambient pressure ion mobility-based instruments, and (iii) high flow rate liquid chromatography mass spectrometry platforms.

5.
J Theor Biol ; 503: 110399, 2020 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-32652085

RESUMEN

In the context of voluntary vaccination, we consider two additional provisions as well as pre-emptive vaccination for a unified model over epidemiology and evolutionary game theory to assess the extent to which advanced and late provisions restrict the spread of disease. To circumvent infection, people can be vaccinated pre-emptively before the epidemic season, but the imperfectness of vaccination or an unwillingness to be vaccinated may cause people instead to either be late-vaccinated or use self-protection. Here, self-protection corresponds to actions such as wearing a mask, washing hands, or using a mosquito net and is defined as the third strategy after pre-emptive vaccination (the first strategy) and late-vaccination (the second strategy). Our model can reproduce multiple social dilemma situations resulting from what is known as the vaccination dilemma (originating from preemptive vaccination), which works on a global time scale (i.e., repeated seasons approaching social equilibrium), and also from two other dilemmas due to late provisions, which work on a local time scale (i.e., every time step in a single season). To reproduce how an individual can acquire information for adaptation from neighbors or the society for a suitable provision, we introduce several strategy-updating rules for both global and local time scales and this behavioral feedback has a significant effect to reducing a transmissible disease. We also establish the social efficiency deficit (SED) indicator for a triple-dilemma game to quantify the existence of a social dilemma. Relying fully on a theoretical framework, our model provides a new perspective for evaluations: (i) how much more advantageous and effective pre-emptive vaccination is in eradicating a communicable disease compared with late provisions such as late vaccination and self-protection, and (ii) the extent of the social dilemma resulting from each of the three provisions, given the new idea of SED. The main effect of the triple-dilemma is that expensive provision displays no SED (no dilemma) until the efficiency or effectiveness of provisions reaches a certain level.


Asunto(s)
Epidemias , Teoría del Juego , Evolución Biológica , Humanos , Vacunación
6.
J Theor Biol ; 503: 110379, 2020 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-32622789

RESUMEN

Records of epidemics acknowledge immunological multi-serotype illnesses as an important aspect of the occurrence and control of contagious diseases. These patterns occur due to antibody-dependent-enhancement (ADE) among serotype diseases, which leads to infection of secondary infectious classes. One example of this is dengue hemorrhagic fever and dengue shock syndrome, which comprises the following four serotypes: DEN-1, DEN-2, DEN-3, and DEN-4. The evolutionary vaccination game approach is able to shed light on this long-standing issue in a bid to evaluate the success of various control programs. Although immunization is regarded as one of the most accepted approaches for minimizing the risk of infection, cost and efficiency are important factors that must also be considered. To analyze the n-serovar aspect alongside ADE consequence in voluntary vaccination, this study establishes a new mathematical epidemiological model that is dovetailed with evolutionary game theory, an approach through which we explored two vaccine programs: primary and secondary. Our findings illuminate that the 'cost-efficiency' effect for vaccination decision exhibits an impact on controlling n-serovar infectious diseases and should be designed in such a manner as to avoid adverse effects. Furthermore, our numerical result justifies the fact that adopting ADE significantly boosted emerging disease incidence, it also suggest that the joint vaccine policy works even better when the complex cyclical epidemic outbreak takes place among multi serotypes interactions. Research also exposes that the primary vaccine is a better controlling tool than the secondary; however, introducing a highly-efficiency secondary vaccine against secondary infection plays a key role to control the disease prevalence.


Asunto(s)
Virus del Dengue , Dengue , Acrecentamiento Dependiente de Anticuerpo , Humanos , Serogrupo , Vacunación
7.
Unfallchirurg ; 123(7): 507-516, 2020 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-32405652

RESUMEN

BACKGROUND: The cost pressure in a competitive environment forces hospitals and physicians to optimize clinical processes. In order to secure competitive advantages, a continuous evaluation of relevant processes is necessary. OBJECTIVE: Administrative and medical processes in a university outpatient department for orthopedics and traumatology were evaluated using the lean method in order to reduce patient waiting times. MATERIAL AND METHODS: Over a period of 2 weeks all patients who were treated in the department for orthopedic and trauma surgery on an outpatient basis were included in the assessment of the process. Personnel in the policlinic were prepared and trained to record times for appointments made by telephone, arrival time at the hospital, first contact, administrative procedure, first contact with the doctor, length of stay in the radiology and anesthesiology departments and completion of treatment. In addition, potential inefficiencies were identified through patient flow analysis and personal interviews with personnel in the administration and outpatient departments as well as residents and senior physicians. RESULTS: A total of 126 patients were enrolled in the study. The average length of stay of patients in the outpatient clinic was 144 min (range 30-371 min). A necessary imaging examination increased the length of stay by an average of 53 min and a necessary premedication by an average of 78 min compared to patients with no further consultations. CONCLUSION: By analyzing the pathways and times of patients, various reasons for waiting times in the university outpatient clinic could be shown. This study shows that a structured application of lean management and a dedicated analysis create added value for patients by reducing waiting times.


Asunto(s)
Ortopedia , Citas y Horarios , Hospitales Universitarios , Humanos , Pacientes Ambulatorios , Traumatología , Listas de Espera
8.
Unfallchirurg ; 123(7): 517-525, 2020 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-32385538

RESUMEN

BACKGROUND: The operating room (OR) accounts for the highest fraction of hospital costs and also has the largest proportion of revenue. Classical goals of optimizing OR efficiency are to increase the quality of treatment and economic success. As the reduction of qualified personnel as the largest cost factor was favored for many years, nowadays a shortage of nursing personnel is threatening the surgery departments in many German hospitals. OBJECTIVE: Which improvements are possible while the OR already suffers from restrictions? What are critical resources, what are the critical burdens and how can they be optimized? MATERIAL AND METHODS: An analysis of the OR organization of an orthopedic and traumatology department with reduced OR capacity due to a shortage of OR and anesthesia nursing personnel was performed. This was followed by the evaluation of possible alterations with the corresponding advantages and disadvantages. After selection and implementation, the qualitative and quantitative differences were examined before and after the alterations. RESULTS: Multifaceted problem areas could be identified. The establishment of a fast track OR with concentration of additional resources on many fast points in an OR instead of on a few complex cases was selected and implemented. The installation of a holding area for patients waiting for surgery eliminated transportation delays almost entirely. Alterations in the OR planning and capacity distribution reduced nocturnal operating times. Despite reduction of the OR capacity both the number of operations performed and the incision to suture times could be increased. CONCLUSION: Optimization of the processes in the OR is possible and necessary, despite the lack of personnel. Even only a few structural changes can eliminate bottlenecks, resulting in qualitative and quantitative improvements.


Asunto(s)
Quirófanos , Anestesia , Hospitales , Humanos , Ortopedia
9.
Unfallchirurg ; 123(7): 526-533, 2020 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-32399650

RESUMEN

BACKGROUND: Due to limited financial and human resources, efficient planning of patient flows, operation preparations and perioperative diagnostics are of great importance. In the present study potential problems and solution strategies in the interdisciplinary collaboration between orthopedic surgeons, trauma surgeons and colleagues in anesthesiology and radiology departments are presented. MATERIAL AND METHODS: After implementation of a process management system, the data were collated and the number of patients, the utilization of external departments in the consultation, waiting times and patient adherence to appointments were analyzed. Patient satisfaction was determined using a questionnaire. In addition, the current literature was searched regarding the topic of process optimization and interdisciplinary cooperation. RESULTS: The waiting time for an appointment in the outpatient clinic consultation in orthopedics and trauma at the University Hospital Bonn was between 9.15 and 11.23 days. Of the patients 10-20% from the consultation presented in the premedication outpatient department. Radiological imaging was performed in 22-28% of the cases. Patient satisfaction was recorded using a questionnaire gathering information on medical treatment, organization and infrastructure as well as treatment success. The importance of an efficient and digitally organized cooperation is generally promoted in the literature; however, there is insufficient data on the subject of process organization and economic interdisciplinary cooperation. CONCLUSION: By implementing a process management, deficiencies in the workflow and interdisciplinary collaboration can be identified and optimized in a structured manner. This also improves patient and employee satisfaction and the quality of treatment.


Asunto(s)
Ortopedia , Instituciones de Atención Ambulatoria , Citas y Horarios , Humanos , Satisfacción del Paciente , Derivación y Consulta
10.
Unfallchirurg ; 123(7): 534-540, 2020 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-32405653

RESUMEN

BACKGROUND: Geriatric patients are currently responsible for almost one third of all emergency hospital admissions. An increase of 50% is expected in the next decade. This age redistribution poses new challenges for inpatient care and discharge management. The requirements of an orthopedic trauma surgery clinic in the care of this patient group can be clarified with the help of this first collaboratively created geriatric orthopedic trauma surgery complex treatment unit of a university hospital. OBJECTIVE: What influence do age and delirium have on discharge management, length of inpatient stay and discharge destination in a geriatric cohort? MATERIAL AND METHODS: All patients who received inpatient treatment as part of the orthopedic trauma surgery geriatric complex treatment (GKB) between May 2017 and December 2019 were evaluated. An analysis of the demographics, length of inpatient stay, discharge destinations and evaluation of the Barthel index collected on admission and discharge, the mini-mental state examination (MMSE) and the geriatric depression scale (GDS) were carried out. RESULTS: Out of 312 patients, 110 men and 193 women with a median age of 81 years, 77 patients (24.6%) showed delirium when enrolled in the GKB and 39 (12.5%) dementia. Older patients presented more often with delirium than younger people (p = 0.013), especially those aged 70-79 years (p = 0.037). Dementia patients suffered more frequently from postoperative delirium (p < 0.01). The mean hospital stay was 17.79 days (±4.6 days). The GKB was regularly completed in 60.7% of all cases and 39.3% patients dropped out early. Patients with delirium were discharged significantly less often into their own home but into short-term care or nursing homes (p = 0.038). A general correlation between delirium development and the discharge destination was noticeable (p = 0.004). CONCLUSION: Patients with dementia are more likely to develop delirium postoperatively, which leads to an increase in the length of inpatient stay, an increase in treatment costs and more work for the discharge management team. In addition, the discharge to the patients' home is impaired by delirium, which means that the growing need for places in short-term care and nursing homes also creates socioeconomic burdens.


Asunto(s)
Traumatología , Anciano de 80 o más Años , Delirio , Femenino , Evaluación Geriátrica , Hospitalización , Humanos , Tiempo de Internación , Masculino , Alta del Paciente
11.
Anal Chem ; 91(18): 11827-11833, 2019 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-31429255

RESUMEN

Methylation of arginine residues in proteins, an enzyme-mediated post-translational modification (PTM), is important for mRNA processing and transport and for the regulation of many protein-protein interactions. However, proteolytic peptides resulting from alternative sites of post-translational methylation have identical masses and cannot be readily separated by standard liquid chromatography-mass spectrometry. Unlike acetylation or phosphorylation, methylation of arginine does not strongly affect the charge states of peptide ions, multiple instances of methylation can occur on a single amino acid residue, and the relative mass of the modification is <1% that of the typical proteolytic peptide. High field asymmetric waveform ion mobility spectrometry (FAIMS) is an orthogonal separation method to liquid chromatography that can rapidly separate gaseous ions prior to detection by mass spectrometry. Here, we report that FAIMS can be used to separate arginine-methylated peptides that differ by the position of a single methyl group for both mono- and dimethylated variants. Although the resolution of separation for these arginine-methylated peptides improved with increasing amounts of helium in the FAIMS carrier gas as expected, we found that the site of methylation can strongly affect the dependence of the electric field used for ion transmission on the extent of helium in the carrier gas. Thus, certain isobaric peptides can be cotransmitted at high helium concentrations whereas lower concentrations can be used for successful separations of such peptide mixtures. The capability to rapidly resolve isobaric arginine-methylated peptides should be useful in the future for the detailed analysis of protein arginine methylation in biological samples.


Asunto(s)
Espectrometría de Masas/métodos , Proteínas Nucleares/química , Péptidos/aislamiento & purificación , Ribonucleoproteínas Nucleolares Pequeñas/química , Proteínas de Saccharomyces cerevisiae/química , Arginina/análogos & derivados , Arginina/química , Arginina/metabolismo , Helio/química , Espectrometría de Movilidad Iónica/métodos , Metilación , Proteínas Nucleares/metabolismo , Péptidos/química , Péptidos/metabolismo , Procesamiento Proteico-Postraduccional , Secuencias Repetitivas de Aminoácido , Ribonucleoproteínas Nucleolares Pequeñas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
12.
Mymensingh Med J ; 26(1): 194-197, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28260775

RESUMEN

Swallowing foreign body in adult is uncommon. This mostly occurs accidentally or in psychologically unsound patient. A 32-years-old male patient with abdominal pain admitted in surgery department of Mymensingh Medical College Hospital, Mymensingh, Bangladesh with a history of swallowing various objects. After endoscopic confirmation and psychological evaluation he underwent laparotomy and 29 different objects were removed from his stomach by Gastrotomy. He was psychiatrically evaluated after recovery from operation and was found to be suffering from Schizophrenia with cannabis use. The aim of reporting this case can raise awareness at the patients complains should be taken seriously to prevent morbidity and even mortality.


Asunto(s)
Cuerpos Extraños , Esquizofrenia , Adulto , Bangladesh , Cuerpos Extraños/cirugía , Humanos , Masculino , Estómago/cirugía
13.
Analyst ; 141(8): 2463-73, 2016 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-26981609

RESUMEN

Piezoelectric acoustic wave devices integrated with noble metal surfaces provide exciting prospects for the direct measurement of toxic gas species such as mercury (Hg) in the atmosphere. Even though gold (Au) based acoustic wave sensors have been utilized extensively for detecting Hg, the potential of using other metal surfaces such as silver (Ag) is yet to be thoroughly studied. Here, we developed Ag sensitive layer-based surface acoustic wave (SAW) and quartz crystal microbalance (QCM) sensors and focused on their comparative analysis for Hg sensing applications with parameters such as the sensor sensitivity, selectivity, adsorption/desorption isotherm and Hg diffusion into the surface thoroughly studied. The SAW sensor was fabricated with nickel (Ni) interdigitated transducer (IDT) electrodes and a Ag thin film on the delay line of the device. In the case of the QCM sensor, the electrodes were constructed of Ag thin film and simultaneously employed as a sensitive layer. Mercury sensing experiments were conducted for a range of concentrations between 24-365 ppbv without/with the presence of some common industrial interfering gas species (i.e. ammonia, acetaldehyde, ethyl mercaptan, dimethyl disulphide, methyl ethyl ketone and humidity) at various operating temperatures in the range of 35-95 °C. The SAW sensor was found to possess up to 70 times higher response magnitudes than its QCM counterpart at 35 °C while up to 30 and 23 times higher response magnitudes were observed for the SAW sensor at elevated temperatures of 75 and 95 °C, respectively. Furthermore, the SAW sensor showed good selectivity (>89%) toward Hg(0) vapor in the presence of all the interferents tested at an operating temperature of 75 °C while the QCM sensor exhibited significant cross-sensitivity when ethyl mercaptan was introduced along with Hg(0) vapor. Overall, it is indicative that Ag-based acoustic wave sensors do have great potential for Hg sensing applications, given that right operating conditions are applied.

14.
Environ Sci Technol ; 50(3): 1384-92, 2016 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-26683634

RESUMEN

We developed a novel conductometric device with nanostructured gold (Au) sensitive layer which showed high-performance for elemental mercury (Hg(0)) vapor detection under simulated conditions that resemble harsh industrial environments. That is, the Hg(0) vapor sensing performance of the developed sensor was investigated under different operating temperatures (30-130 °C) and working conditions (i.e., humid) as well as in the presence of various interfering gas species, including ammonia (NH3), hydrogen sulfide (H2S), nitric oxide (NO), carbon mono-oxide (CO), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen (H2), methane (CH4), and volatile organic compounds (VOCs) such as ethylmercaptan (EM), acetaldehyde (MeCHO) and methyl ethyl ketone (MEK) among others. The results indicate that the introduction of Au nanostructures (referred to as nanospikes) on the sensor's surface enhanced the sensitivity toward Hg(0) vapor by up-to 450%. The newly developed sensor exhibited a limit of detection (LoD) (∼35 µg/m(3)), repeatability (∼94%), desorption efficiency (100%) and selectivity (∼93%) when exposed to different concentrations of Hg(0) vapor (0.5 to 9.1 mg/m(3)) and interfering gas species at a chosen operating temperature of 105 °C. Furthermore, the sensor was also found to show 91% average selectivity when exposed toward harsher industrial gases such as NO, CO, CO2, and SO2 along with same concentrations of Hg(0) vapor in similar operating conditions. In fact, this is the first time a conductometric sensor is shown to have high selectivity toward Hg(0) vapor even in the presence of H2S. Overall results indicate that the developed sensor has immense potential to be used as accurate online Hg(0) vapor monitoring technology within industrial processes.


Asunto(s)
Gases/química , Mercurio/química , Nanotecnología/instrumentación , Compuestos Orgánicos Volátiles/química , Amoníaco , Dióxido de Carbono , Oro/química , Sulfuro de Hidrógeno , Límite de Detección , Dióxido de Azufre
15.
Langmuir ; 31(30): 8519-29, 2015 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-26169072

RESUMEN

Microelectromechanical sensors based on surface acoustic wave (SAW) and quartz crystal microbalance (QCM) transducers possess substantial potential as online elemental mercury (Hg(0)) vapor detectors in industrial stack effluents. In this study, a comparison of SAW- and QCM-based sensors is performed for the detection of low concentrations of Hg(0) vapor (ranging from 24 to 365 ppbv). Experimental measurements and finite element method (FEM) simulations allow the comparison of these sensors with regard to their sensitivity, sorption and desorption characteristics, and response time following Hg(0) vapor exposure at various operating temperatures ranging from 35 to 75 °C. Both of the sensors were fabricated on quartz substrates (ST and AT cut quartz for SAW and QCM devices, respectively) and employed thin gold (Au) layers as the electrodes. The SAW-based sensor exhibited up to ∼111 and ∼39 times higher response magnitudes than did the QCM-based sensor at 35 and 55 °C, respectively, when exposed to Hg(0) vapor concentrations ranging from 24 to 365 ppbv. The Hg(0) sorption and desorption calibration curves of both sensors were found to fit well with the Langmuir extension isotherm at different operating temperatures. Furthermore, the Hg(0) sorption and desorption rate demonstrated by the SAW-based sensor was found to decrease as the operating temperature increased, while the opposite trend was observed for the QCM-based sensor. However, the SAW-based sensor reached the maximum Hg(0) sorption rate faster than the QCM-based sensor regardless of operating temperature, whereas both sensors showed similar response times (t90) at various temperatures. Additionally, the sorption rate data was utilized in this study in order to obtain a faster response time from the sensor upon exposure to Hg(0) vapor. Furthermore, comparative analysis of the developed sensors' selectivity showed that the SAW-based sensor had a higher overall selectivity (90%) than did the QCM counterpart (84%) while Hg(0) vapor was measured in the presence of ammonia (NH3), humidity, and a number of volatile organic compounds at the chosen operating temperature of 55 °C.


Asunto(s)
Oro/química , Mercurio/química , Sistemas Microelectromecánicos , Tecnicas de Microbalanza del Cristal de Cuarzo , Sonido , Adsorción , Tamaño de la Partícula , Propiedades de Superficie
16.
Analyst ; 140(16): 5508-17, 2015 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-26065560

RESUMEN

The detection of elemental mercury (Hg(0)) within industrial processes is extremely important as it is the first major step in ensuring the efficient operation of implemented mercury removal technologies. In this study, a 131 MHz surface acoustic wave (SAW) delay line sensor with gold electrodes was tested towards Hg(0) vapor (24 to 365 ppbv) with/without the presence of ammonia (NH3) and humidity (H2O), as well as volatile organic compounds (VOCs) such as acetaldehyde (MeCHO), ethylmercaptan (EM), dimethyl disulfide (DMDS) and methyl ethyl ketone (MEK), which are all common interfering gas species that co-exist in many industrial applications requiring mercury monitoring. The developed sensor exhibited a detection limit of 0.7 ppbv and 4.85 ppbv at 35 and 55 °C, respectively. Furthermore, a repeatability of 97% and selectivity of 92% in the presence of contaminant gases was exhibited by the sensor at the chosen operating temperature of 55 °C. The response magnitude of the developed SAW sensor towards different concentrations of Hg(0) vapor fitted well with the Langmuir extension isotherm (otherwise known as loading ratio correlation (LRC)) which is in agreement with our basic finite element method (FEM) work where an LRC isotherm was observed for a simplified model of the SAW sensor responding to different Hg contents deposited on the Au based electrodes. Overall, the results indicate that the developed SAW sensor can be a potential solution for online selective detection of low concentrations of Hg(0) vapor found in industrial stack effluents.


Asunto(s)
Electrodos , Gases/análisis , Oro/química , Mercurio/análisis , Modelos Teóricos , Sonido , Compuestos Orgánicos Volátiles/química
18.
Unfallchirurg ; 118(6): 484-9, 2015 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-25956726

RESUMEN

Injuries to the hand and wrist are common sports injuries. The diagnosis and therapy of wrist injuries are becoming more important, especially in increasingly more popular ball-hitting sports, such as golf, tennis and baseball. Ulnar-sided wrist pain is initially often misdiagnosed and treated as tenosynovitis or tendinitis but tears of the triangular fibrocartilage complex (TFCC) and fractures of the hook of hamate bone, which can also occur in these sports are seldomly diagnosed. The aim of this study was to conduct a systematic review of the literature focussing on TFCC lesions and fractures of the hook of the hamate bone in racquet sports, baseball and golf. A systematic review of the literature was performed in PubMed on the occurrence of TFCC lesions and fractures of the hook of the hamate bone. All studies and case reports were included. Because of the rarity of these injuries there were no exclusion criteria concerning the number of cases. Injuries associated with ball-hitting sports, such as TFCC lesions and fractures of hook of the hamate bone are still underrepresented in the current literature on sports injuries. The diagnosis and treatment of these injuries are often delayed and can severely handicap the performance and career of affected professional as well as amateur athletes.


Asunto(s)
Artralgia/diagnóstico , Traumatismos en Atletas/diagnóstico , Fracturas Óseas/diagnóstico , Hueso Ganchoso/lesiones , Fibrocartílago Triangular/lesiones , Traumatismos de la Muñeca/diagnóstico , Artralgia/etiología , Traumatismos en Atletas/complicaciones , Diagnóstico Diferencial , Fracturas Óseas/complicaciones , Higiene de las Manos , Humanos , Traumatismo Múltiple/complicaciones , Traumatismo Múltiple/diagnóstico , Cúbito , Traumatismos de la Muñeca/complicaciones
20.
Heliyon ; 10(11): e32308, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38873680

RESUMEN

Evolutionary epidemiology models have substantially impacted the study of various infections and prevention methods in the biology field. These models are called Susceptible, Lockdown, Vaccinated, Infected, and Recovered (SLVIR) epidemic dynamics. We explore how human behavior, particularly in the context of disease transmission, is influenced by two intervention strategies: vaccination and lockdown, both of which are grounded in the principles of evolutionary game theory (EGT). This comprehensive study using evolutionary game theory delves into the dynamics of epidemics, explicitly focusing on the transition rate from susceptibility to immunity and susceptibility to lockdown measures. Our research involves a thorough analysis of the structural aspects of the SLVIR epidemic model, which delineates disease-free equilibria to ensure stability in the system. Our investigation supports the notion that implementing lockdown measures effectively reduces the required level of vaccinations to curtail the prevalence of new infections. Furthermore, it highlights that combining both strategies is particularly potent when an epidemic spreads rapidly. In regions where the disease spreads comparatively more, our research demonstrates that lockdown measures are more effective in reducing the spread of the disease than relying solely on vaccines. Through significant numerical simulations, our research illustrates that integrating lockdown measures and efficient vaccination strategies can indirectly lower the risk of infection within the population, provided they are both dependable and affordable. The outcomes reveal a nuanced and beneficial scenario where we examine the interplay between the evolution of vaccination strategies and lockdown measures, assessing their coexistence through indicators of average social payoff.

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