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1.
Sensors (Basel) ; 23(2)2023 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-36679432

RESUMEN

The need to reduce greenhouse gas emissions from power generation has led to more and more installation of renewable energies such as wind and solar power. However, the high intermittency of these generators poses a threat to electrical grid stability. The power output of solar photovoltaic (PV) installations, for instance, depends on the solar irradiance, and consequently on weather conditions. In order to mitigate the adverse effects of solar intermittency, storage such as batteries can be deployed. However, the cost of a stationary energy storage system (SESS) is high, particularly for large PV installations. Battery electric vehicles (BEVs) are an alternative to SESS. With increasing number of BEVs, more and more storage capacity becomes available while these vehicles are charging. In this paper, we compare stationary batteries to mobile batteries of battery electric buses (BEBs) in a public bus terminus for balancing fluctuations of solar PV installations. Public buses have been chosen due to their large batteries and because they are more easily manageable than private cars. An optimisation model has been developed considering both the bus operator's and the PV operator's objectives. Cycle ageing of batteries is included in the investigation. Our analysis reveals that utilising public BEBs with high battery capacity to balance solar PV fluctuations can present a positive financial case.


Asunto(s)
Electricidad , Energía Solar , Energía Renovable , Viento , Vehículos a Motor
2.
Indian J Palliat Care ; 26(2): 164-172, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32874029

RESUMEN

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group (SIG) guidelines, for the diagnosis and assessment of cancer pain in adults provide a structured, step-wise approach which will help to improve the management of cancer pain and to provide the patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs of patient population and situations in India. A questionnaire based on the key elements of each sub draft addressing certain inconclusive areas where evidence was lacking, was made available on the ISSP website and circulated by E-mail to all the ISSP and Indian Association of Palliative Care (IAPC) members. We recommend that a comprehensive pain assessment of all the patients should be conducted before initiating treatment. The patients should be educated about all the available pain control interventions. For assessing cancer pain, unidimensional tools such as Numeric Rating Scale, Visual Analog Scale, and Visual Rating Scale should always be used routinely. Patients with cancer pain should routinely be screened for distress and other psychological disorders, using the Patient Health Questionnaire-9. The most reliable assessment of pain is patients' self-reporting.

3.
Indian J Palliat Care ; 26(2): 180-190, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32874031

RESUMEN

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group (SIG) guidelines on pharmacological management of cancer pain in adults provide a structured, stepwise approach, which will help to improve the management of cancer pain and to provide the patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire, based on the key elements of each sub draft addressing certain inconclusive areas where evidence was lacking, was made available on the ISSP website and circulated by e-mail to all the ISSP and Indian Association of Palliative Care members. We recommend that analgesics for cancer pain management should follow the World Health Organization 3-step analgesic ladder appropriate for the severity of pain. The use of paracetamol and nonsteroidal anti-inflammatory drugs alone or in combination with opioids for mild-to-moderate pain should be used. For mild-to-moderate pain, weak opioids such as tramadol, tapentadol, and codeine can be given in combination with nonopioid analgesics. We recommend morphine as the opioid of the first choice for moderate-to-severe cancer pain. Sustained-release formulations can be started 12 hourly, once the effective 24 h dose with immediate-release morphine is established. Opioid switch or rotation should be considered if there is inadequate analgesia or intolerable side effects. For opioid-induced respiratory depression, µ receptor antagonists (e.g. naloxone) must be used promptly. Antidepressants and/or anticonvulsants should be used to treat neuropathic cancer pain, and the dose should be titrated according to the clinical response and side effects. External beam radiotherapy should be offered to all patients with painful metastatic bone pain. There is evidence on use of ketamine in cancer neuropathic pain, but with no beneficial effect, thus, it is not recommended.

4.
Indian J Palliat Care ; 26(2): 198-202, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32874033

RESUMEN

The Indian Society for Study of Pain (ISSP), cancer pain Special Interest Group (SIG) guidelines on complementary therapies for cancer pain in adults provides a structured, stepwise approach which will help to improve the management of cancer pain and to provide the patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire based on the key elements of each sub drafts addressing certain inconclusive areas where evidence was lacking, was made available on the ISSP website and circulated by e-mail to all the ISSP and Indian Association of Palliative Care members. We recommend that psychological interventions, including psychoeducation, are useful and should be considered in patients with cancer pain and psychological distress. Furthermore, physical and complementary treatment can be used as an adjunctive therapy for patients with cancer pain.

5.
Indian J Palliat Care ; 26(2): 191-197, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32874032

RESUMEN

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group, guidelines on pharmacological management of cancer pain in adults provide a structured, step-wise approach which will help to improve the management of cancer pain and to provide patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire based on the key elements of each sub draft addressing certain inconclusive areas where evidence was lacking, was made available on the ISSP website and circulated by E-mail to all the ISSP and Indian Association of Palliative Care members. Antidepressants and/or anticonvulsants should be used to treat neuropathic cancer pain and the dose should be titrated according to the clinical response and side effects. External beam radiotherapy should be offered to all patients with painful metastatic bone pain. There is evidence on the use of ketamine in cancer neuropathic pain, but with no beneficial effect, thus it is not recommended.

6.
Indian J Palliat Care ; 26(2): 210-214, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32874035

RESUMEN

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group guidelines on palliative care aspects in cancer pain in adults provide a structured, stepwise approach which will help to improve the management of cancer pain and to provide the patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire based on the key elements of each sub draft addressing certain inconclusive areas where evidence was lacking was made available on the ISSP website and circulated by E-mail to all the ISSP and Indian Association of Palliative Care (IAPC) members. In a cancer care setting, approaches toward managing pain vary between ambulatory setting, home care setting, acute inpatient setting, and end-of-life care in hospice setting. We aim to expound the cancer pain management approaches in these settings. In an ambulatory palliative care setting, the WHO analgesic step ladder is used for cancer pain management. The patients with cancer pain require admission for acute inpatient palliative care unit for poorly controlled pain in ambulatory and home care settings, rapid opioid titration, titration of difficult drugs such as methadone, acute pain crisis, pain neuromodulation, and pain interventions. In a palliative home care setting, the cancer pain is usually assessed and managed by nurses and primary physicians with a limited input from the specialist physicians. In patients with cancer at the end of life, the pain should be assessed at least once a day. Moreover, physicians should be trained in assessing patients with pain who are unable to verbalize or have cognitive impairment.

7.
Indian J Palliat Care ; 26(2): 173-179, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32874030

RESUMEN

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group guidelines on pharmacological management of cancer pain in adults provides a structured, step-wise approach which will help to improve the management of cancer pain and to provide the patients with a minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire based on the key elements of each sub drafts addressing certain inconclusive areas where evidence was lacking, was made available on the ISSP website, and circulated by E-mail to all the ISSP and Indian Association of Palliative Care (IAPC) members. We recommend that analgesics for cancer pain management should follow the World Health Organization three-step analgesic ladder appropriate for the severity of pain. The use of paracetamol and nonsteroidal anti-inflammatory drugs alone or in combination with opioids for mild-to-moderate pain should be used. For mild-to-moderate pain, weak opioids such as tramadol, tapentadol, and codeine can be given in combination with nonopioid analgesics. We recommend morphine as the opioid of first choice for moderate-to-severe cancer pain.

8.
Indian J Palliat Care ; 26(2): 203-209, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32874034

RESUMEN

The Indian Society for Study of Pain (ISSP), Cancer Pain Special Interest Group guidelines on interventional management for cancer pain in adults provide a structured, stepwise approach which will help to improve the management of cancer pain and to provide the patients with minimally acceptable quality of life. The guidelines have been developed based on the available literature and evidence, to suit the needs, patient population, and situations in India. A questionnaire based on the key elements of each sub draft addressing certain inconclusive areas where evidence was lacking was made available on the ISSP website and circulated by e-mail to all the ISSP and Indian Association of Palliative Care members. We recommend using interventional management when conventional therapy fails to offer adequate benefits or causes undesirable side effects. Vertebroplasty should be offered to patients with uncontrolled bone pain when expertise is available.

9.
Mass Spectrom Rev ; 37(6): 811-853, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-29603316

RESUMEN

The isotopic exchange approach is in use since the first observation of such reactions in 1933 by Lewis. This approach allows the investigation of the pathways of chemical and biochemical reactions, determination of structure, composition, and conformation of molecules. Mass spectrometry has now become one of the most important analytical tools for the monitoring of the isotopic exchange reactions. Investigation of conformational dynamics of proteins, quantitative measurements, obtaining chemical, and structural information about individual compounds of the complex natural mixtures are mainly based on the use of isotope exchange in combination with high resolution mass spectrometry. The most important reaction is the Hydrogen/Deuterium exchange, which is mainly performed in the solution. Recently we have developed the approach allowing performing of the Hydrogen/Deuterium reaction on-line directly in the ionization source under atmospheric pressure. Such approach simplifies the sample preparation and can accelerate the exchange reaction so that certain hydrogens that are considered as non-labile will also participate in the exchange. The use of in-ionization source H/D exchange in modern mass spectrometry for structural elucidation of molecules serves as the basic theme in this review. We will focus on the mechanisms of the isotopic exchange reactions and on the application of in-ESI, in-APCI, and in-APPI source Hydrogen/Deuterium exchange for the investigation of petroleum, natural organic matter, oligosaccharides, and proteins including protein-protein complexes. The simple scenario for adaptation of H/D exchange reactions into mass spectrometric method is also highlighted along with a couple of examples collected from previous studies.

10.
Rapid Commun Mass Spectrom ; 33(7): 650-656, 2019 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-30710409

RESUMEN

RATIONALE: Molecular dynamics (MD) simulations with finite temperature were performed to improve the theoretical prediction of collisional cross section (CCS) values, especially for aromatic compounds containing long alkyl chains. METHODS: In this study, the CCS values of 11 aromatic compounds with long alkyl chains were calculated by MD simulations while considering internal energy at 300, 500, and 700 K, and the results were compared with experimentally determined values. RESULTS: The CCS values calculated at higher energies showed better agreement with the experimental values. Polycyclic aromatic hydrocarbons (PAHs) such as pentacene and benz[b]anthracene were also investigated, and better agreement between the theoretical and experimental results was observed when higher temperature (or higher internal energy) was considered. CONCLUSIONS: The data presented in this study show that the internal degrees of freedom of ions must be considered to accurately predict the CCS values of aromatic compounds with a flexible structure measured by ion mobility mass spectrometry.

11.
Pain Pract ; 19(1): 16-26, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-29761638

RESUMEN

INTRODUCTION: Among the elderly population, chronic osteoarthritis of the knee joint is one of the leading causes of disability and causes considerable pain, joint stiffness, and functional limitations. Although knee replacement is a good option for advanced osteoarthritis, many patients could not undergo surgery due to comorbidities or other reasons. METHODS: Four patients with severe pain from grade 3 and 4 osteoarthritis of the knee had undergone ultrasound-guided alcohol neurolysis of the 6 genicular nerves after a positive genicular nerve block with local anesthetics. The demographics, pain intensity (NRS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and quality of life (SF-36) were analyzed. RESULTS: There was significant improvement in pain intensity at rest, on movement, and on weight bearing after the neurolysis and it has continued for 6 months (P < 0.05). The OKS and WOMAC score had improved from 7.75 ± 1.25 and 77.75 ± 4.34 at baseline, to 20.75 ± 1.70 and 56.25 ± 3.09 at 1 month, and to 18.25 ± 0.95 and 52.00 ± 2.16 at 6 months after the procedure, respectively (P < 0.05). There was also significant improvement in the quality of life after the procedure (P < 0.05). CONCLUSION: Ultrasound-guided alcohol neurolysis is a good alternative for patients having severe pain from knee osteoarthritis and provides significant pain relief for more than 6 months.


Asunto(s)
Bloqueo Nervioso/métodos , Osteoartritis de la Rodilla/complicaciones , Manejo del Dolor/métodos , Dolor Intratable/cirugía , Anciano , Etanol , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor Intratable/etiología , Calidad de Vida , Resultado del Tratamiento
12.
Rapid Commun Mass Spectrom ; 32(12): 973-980, 2018 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-29600539

RESUMEN

RATIONALE: The ionization process is essential for successful mass spectrometric (MS) analysis because of its influence on selectivity and sensitivity. In particular, certain solvents reduce the ionization of the analyte, thereby reducing the overall sensitivity in atmospheric pressure photoionization (APPI). Since the sensitivity varies greatly depending on the solvents, a fundamental understanding of the mechanism is required. METHODS: Standard solutions were analyzed using a (+)-APPI Q Exactive ion trap mass spectrometer (Thermo Scientific). Each solution was infused directly into the APPI source at a flow rate of 100 µL/min and the APPI source temperature was 300°C. Other operating mass spectrometric parameters were maintained under the same conditions. Quantum mechanical calculations were carried out using the Gaussian 09 suite program. RESULTS: Density functional theory was used to calculate the reaction enthalpies (∆H) of the reactions between toluene and other solvents. The experimental and theoretical results showed good agreement. The abundances of analyte ions were well correlated with the calculated ∆H values. Therefore, the results strongly support the suggested signal reduction mechanism. In addition, linear correlations between the abundance of toluene and analyte molecular ions were observed, which also supports the suggested mechanism. CONCLUSIONS: A solvent composition dependent signal reduction mechanism was suggested and evaluated for the (+)-APPI-MS analysis of polyaromatic hydrocarbons (PAHs) generating mainly molecular ions. Overall, the evidence provided in this work suggests that reactions between solvent cluster(s) and toluene molecular ions are responsible for the observed reductions in signal.

13.
Rapid Commun Mass Spectrom ; 31(12): 1023-1030, 2017 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-28401729

RESUMEN

RATIONALE: The theoretical enthalpy calculated from the overall protonation reaction (electron transfer plus hydrogen transfer) in positive-mode (+) atmospheric-pressure photoionization (APPI) was compared with experimental results for 49 aromatic compounds. A linear relationship was observed between the calculated ΔH and the relative abundance of the protonated peak. The parameter gives reasonable predictions for all the aromatic hydrocarbon compounds used in this study. METHODS: A parameter is devised by combining experimental MS data and high-level theoretical calculations. A (+) APPI Q Exactive Orbitrap mass spectrometer was used to obtain MS data for each solution. B3LYP exchange-correlation functions with the standard 6-311+G(df,2p) basis set was used to perform density functional theory (DFT) calculations. RESULTS: All the molecules with ΔH <0 kcal/mol for the overall protonation reaction with toluene clusters produced protonated ions, regardless of the desolvation temperature. For molecules with ΔH >0, molecular ions were more abundant at typical APPI desolvation temperatures (300°C), while the protonated ions became comparable or dominant at higher temperatures (400°C). The toluene cluster size was an important factor when predicting the ionization behavior of aromatic hydrocarbon ions in (+) APPI. CONCLUSIONS: The data used in this study clearly show that the theoretically calculated reaction enthalpy (ΔH) of protonation with toluene dimers can be used to predict the protonation behavior of aromatic compounds. When compounds have a negative ΔH value, the types of ions generated for aromatic compounds could be very well predicted based on the ΔH value. The ΔH can explain overall protonation behavior of compounds with ΔH values >0. Copyright © 2017 John Wiley & Sons, Ltd.

14.
Indian J Palliat Care ; 23(3): 274-281, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28827930

RESUMEN

INTRODUCTION: The pain from upper gastrointestinal malignancy leads to considerable morbidity. The celiac plexus and splanchnic nerve neurolysis are good therapeutic options. Although splanchnic nerve neurolysis less frequently performed, but it has an edge over celiac plexus as it can be performed in patients with altered celiac plexus anatomy by enlarged lymph nodes. METHODS: The fluoroscopy-guided splanchnic nerve neurolysis was done in about 21 patients with intractable upper abdominal pain with pain intensity of ≥7 in numerical rating scale (NRS) from upper gastrointestinal cancers with distorted celiac plexus anatomy from enlarged celiac lymph nodes as seen by computed tomography scan after positive diagnostic splanchnic nerve neurolysis. The demographic features, pain intensity, daily opioid dose, functional status and quality of life was measured at baseline and 1 week, 1 and 3 months after the procedure. RESULTS: There was a significant improvement in pain intensity, opioid requirement, functional status, and physical components quality of life after the neurolysis (P < 0.05) and this improvement had continued till 3 months. There were also more than 50% reduction in pain intensity and significant decrease in opioid requirement in all the patients after neurolysis. CONCLUSION: The fluoroscopy-guided splanchnic nerve neurolysis results significant pain relief, decrease in opioid intake, improvement in functional status, and quality of life for up to 3 months in upper abdominal pain from gastrointestinal cancers in patients with distorted celiac lymph node anatomy not amenable to celiac plexus neurolysis.

15.
Indian J Palliat Care ; 23(1): 24-35, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28216859

RESUMEN

INTRODUCTION: The phantom limb pain (PLP) and phantom limb sensation (PLS) are very common among amputated cancer patients, and they lead to considerable morbidity. In spite of this, there is a lack of epidemiological data of this phenomenon among the Asian population. This study was done to provide the data from Indian population. METHODS: The prevalence of PLP, stump pain (SP), and PLS was prospectively analyzed from the amputated cancer patients over a period of 2 years in Dr. B.R.A. Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, New Delhi. The risk factors and the impact of phantom phenomenon on patients were also noted. RESULTS: The prevalence of PLP was 41% at 3 and 12 months and 45.3% at 6 months, whereas that of SP and PLS was 14.4% and 71.2% at 3 months, 18.75% and 37.1% at 6 months, 15.8% and 32.4% at 12 months, respectively. There was higher prevalence of PLP and PLS among the patients with history of preamputation pain, smoking with proximal level of amputation, receiving general anesthesia, receiving intravenous (IV) opioid postoperative analgesia, and developing neuroma or infection. CONCLUSION: The prevalence of PLP and PLS was higher among the cancer amputees as compared to SP, and a few risk factors responsible for their higher prevalence were found in our study. The PLP and PLS lead to considerable morbidity in terms of sleep disturbance and depression.

16.
Mass Spectrom Rev ; 34(2): 248-63, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-24942384

RESUMEN

Because of the increasing importance of heavy and unconventional crude oil as an energy source, there is a growing need for petroleomics: the pursuit of more complete and detailed knowledge of the chemical compositions of crude oil. Crude oil has an extremely complex nature; hence, techniques with ultra-high resolving capabilities, such as Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), are necessary. FT-ICR MS has been successfully applied to the study of heavy and unconventional crude oils such as bitumen and shale oil. However, the analysis of crude oil with FT-ICR MS is not trivial, and it has pushed analysis to the limits of instrumental and methodological capabilities. For example, high-resolution mass spectra of crude oils may contain over 100,000 peaks that require interpretation. To visualize large data sets more effectively, data processing methods such as Kendrick mass defect analysis and statistical analyses have been developed. The successful application of FT-ICR MS to the study of crude oil has been critically dependent on key developments in FT-ICR MS instrumentation and data processing methods. This review offers an introduction to the basic principles, FT-ICR MS instrumentation development, ionization techniques, and data interpretation methods for petroleomics and is intended for readers having no prior experience in this field of study.


Asunto(s)
Electrones , Hidrocarburos/aislamiento & purificación , Espectrometría de Masas/instrumentación , Petróleo/análisis , Ciclotrones , Análisis de Fourier , Rayos Láser , Espectrometría de Masas/métodos , Reconocimiento de Normas Patrones Automatizadas , Espectrometría de Masa por Ionización de Electrospray
17.
Anal Bioanal Chem ; 408(12): 3281-93, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26898203

RESUMEN

This paper presents a detailed investigation of the feasibility of optimized positive and negative atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) and atmospheric pressure photoionization (APPI) MS coupled to hydrogen-deuterium exchange (HDX) for structural assignment of diverse oxygen-containing compounds. The important parameters for optimization of HDX MS were characterized. The optimized techniques employed in the positive and negative modes showed satisfactory HDX product ions for the model compounds when dichloromethane and toluene were employed as a co-solvent in APCI- and APPI-HDX, respectively. The evaluation of the mass spectra obtained from 38 oxygen-containing compounds demonstrated that the extent of the HDX of the ions was structure-dependent. The combination of information provided by different ionization techniques could be used for better speciation of oxygen-containing compounds. For example, (+) APPI-HDX is sensitive to compounds with alcohol, ketone, or aldehyde substituents, while (-) APPI-HDX is sensitive to compounds with carboxylic functional groups. In addition, the compounds with alcohol can be distinguished from other compounds by the presence of exchanged peaks. The combined information was applied to study chemical compositions of degraded oils. The HDX pattern, double bond equivalent (DBE) distribution, and previously reported oxidation products were combined to predict structures of the compounds produced from oxidation of oil. Overall, this study shows that APCI- and APPI-HDX MS are useful experimental techniques that can be applied for the structural analysis of oxygen-containing compounds.

18.
Rapid Commun Mass Spectrom ; 29(21): 2095-101, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-26443412

RESUMEN

RATIONALE: Understanding the mechanism of atmospheric pressure photoionization (APPI) is important for studies employing APPI liquid chromatography/mass spectrometry (LC/MS). In this study, the APPI mechanism for polyaromatic hydrocarbon (PAH) compounds dissolved in toluene and methanol or water mixture was investigated by use of MS analysis and quantum mechanical simulation. In particular, four different mechanisms that could contribute to the signal reduction were considered based on a combination of MS data and quantum mechanical calculations. METHODS: The APPI mechanism is clarified by combining MS data and density functional theory (DFT) calculations. To obtain MS data, a positive-mode (+) APPI Q Exactive Orbitrap mass spectrometer was used to analyze each solution. DFT calculations were performed using the general atomic and molecular electronic structure system (GAMESS). RESULTS: The experimental results indicated that methanol significantly reduced the signal in (+) APPI, but no significative signal reduction was observed when water was used as a co-solvent with toluene. The signal reduction is more significant especially for molecular ions than for protonated ions. Therefore, important information about the mechanism of methanol-induced signal reduction in (+) APPI-MS can be gained due its negative impact on APPI efficiency. CONCLUSIONS: The size-dependent reactivity of methanol clusters ((CH3 OH)n , n = 1-8) is an important factor in determining the sensitivity of (+) APPI-MS analyses. Clusters can compete with toluene radical ions for electrons. The reactivity increases as the sizes of the methanol clusters increase and this effect can be caused by the size-dependent ionization energy of the solvent clusters. The resulting increase in cluster reactivity explains the flow rate and temperature-dependent signal reduction observed in the analytes. Based on the results presented here, minimizing the sizes of methanol clusters can improve the sensitivity of LC/(+)-APPI-MS.

19.
Anal Chem ; 86(7): 3300-7, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24592806

RESUMEN

Ultrahigh-resolution mass spectrometry has allowed the determination of elemental formulas of the compounds comprising crude oils. However, elucidating molecular structures remains an analytical challenge. Herein, we propose and demonstrate an approach combining ion mobility mass spectrometry (IM-MS), ultrahigh-resolution mass spectrometry, and theoretical collisional cross-section (CCS) calculations to determine the molecular structures of aromatic compounds found in crude oils. The approach is composed of three steps. First, chemical structures are suggested based on the elemental formulas determined from ultrahigh-resolution mass spectra. Second, theoretical CCS values are calculated based on these proposed structures. Third, the calculated CCS values of the proposed structures are compared with experimentally determined CCS values from IM-MS data to provide proposed structures. For proof of concept, 31 nonalkylated and short-chain alkyl (n < 5, (CH2)n) aromatic compounds commonly observed in crude oils were analyzed. Theoretical and experimental CCS values matched within a 5% RMS error. This approach was then used to propose structures of compounds in selected m/z regions of crude oil samples. Overall, the combination of ion mobility mass spectrometry, ultrahigh-resolution mass spectrometry, and theoretical calculations was shown to be a useful tool for elucidating chemical structures of compounds in complex mixtures.

20.
Indian J Med Res ; 139(2): 216-25, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24718395

RESUMEN

Breast cancer is one of the most prevalent cancers amongst women in the world. Unfortunately, even after adequate treatment, some patients experience severe pain either due to disease progression or due to treatment related side effects. The persistent pain causes a negative physical and psychosocial impact on patients' lives. Current rational pain management is patient-centred and requires a thorough psychological assessment. Usually adequate analgesia is achieved by adopting the WHO's three step analgesic ladder. As the disease progresses, the pain experienced by the patient also increases. This necessitates the administration of opioids and adjuvant analgesics to the breast cancer patients experiencing severe pain. However, opioid use is associated with intolerable side effects like constipation, nausea, vomiting, fear of dependence, and tolerance. Concomitant medications are required to combat these unacceptable side effects. Adjuvant analgesics need to be added to provide adequate and satisfactory analgesia. These factors worsen the psychological state of patients and deteriorate their quality of life. Hence, there is a need to develop therapeutic modalities to provide adequate analgesia with minimum side effects. This review article focuses on the current treatments available for cancer pain management, their limitations, and novel targets and non-pharmacological measures under investigation which have the potential to produce a radical change in pain management measures for the breast cancer patients.


Asunto(s)
Analgésicos Opioides/administración & dosificación , Neoplasias de la Mama/tratamiento farmacológico , Manejo del Dolor , Dolor/tratamiento farmacológico , Analgésicos/administración & dosificación , Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/patología , Femenino , Humanos , Dolor/etiología , Dolor/patología , Calidad de Vida
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