Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Heliyon ; 9(10): e20874, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37867885

RESUMO

To address the global alarm of desertification and boost plant progress in arid and desert environments, super-hydrophobic sand has been suggested and fabricated in numerous researches. In the present work, sand was hydrophobized by coating with a mixture of paraffin wax and silicone oils. The contact angle (CA) of sand with 4.5 w% silicone oils increased from 143.2° to 154.2° with decreasing the chain size of silicone oil, and the further addition of 13.5 w% of paraffin wax produced a super hydrophobic sand with a CA value up to 160° comparing to 154.2° without added paraffin wax. The Fourier Transform Infrared spectra suggested the development of inter molecular forces between silicone oil and sand as well as between paraffin and silicone oil, the driving force of which was the variation in viscosity of silicone oils. The later was higher in the case of lower molecular weight silicone oil. In particular, analyzing the characteristic bands of -(CH2)n-in paraffin wax, i.e. the corresponding bands at 720, 730, 1460 and 1470 cm-1 and the two bands at 1020 and 1095 cm-1 of silicone oil revealed that two roles of paraffin were taking place. While paraffin was placed between sand and silicone oil, it coated the sand particles when lower molecular weight silicone oil was used in the first procedures, whereas it coated the higher molecular weight silicone oil in the second procedures. Molecular dynamic calculation has been performed and confirmed the previous reached conclusions and showed that paraffin molecules were encapsulated in a silicone oil shell. The average adsorption energy of paraffin and silicon oil molecules on sand particles were 29.5 and 38.9 kcal mol-1 respectively.

2.
Sci Rep ; 13(1): 9810, 2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37330582

RESUMO

Sand based superhydrophobic materials, such as paraffin-coated sand, are the focus of global research to fight land desertification. The present work investigates the development of paraffin-coated sand with extending service life as well as improving and stabilizing hydrophobic property by adding plastic waste. While the addition of polyethylene (PE) did not improve the hydrophobic property of paraffin coated sand, incorporating 4.5% of polystyrene (PS) in the composition of coated sand increased the contact angle. Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction patterns (XRD) and two-dimensional correlation spectroscopy (2D-COS) indicated that PS increased the molecular orientation of sand and reduced the thickness of the paraffin coating. Paraffin on the other hand improved the distribution of PS and prevented aggregation with sand. Both FTIR bands at 1085 cm-1 and 462 cm-1 were more sensitive to change in PS contents, while other bands at 780 cm-1 and 798 cm-1 were more sensitive to change in paraffin contents. Moreover, the XRD patterns of sand were split into two components by the addition of PS indicating the transformation of morphology to less ordered or more distorted form. 2D-COS is a powerful tool to reveal harmony of components in mixtures, extract information related to the role of each of them, and help in decision-making process regarding choosing the appropriate recipes.


Assuntos
Poliestirenos , Areia , Parafina , Polietileno/química , Espectroscopia de Infravermelho com Transformada de Fourier
3.
Appl Radiat Isot ; 153: 108806, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31325797

RESUMO

PVA/CMC/HEA based cross-linked hydrogels were synthesized. These were utilized as matrix chloramphenicol drug releasing systems. Combination of different analytical techniques was applied to understand drug releasing process. Ion beam analysis (IBA) measurements, namely micro-PIXE analysis, were applied to gain information regarding spatial distribution of chloramphenicol within the system. Independent complement measurements utilizing UV and pore volume measurements were also employed to additionally characterize and verify the experimental findings obtained by IBA techniques. FTIR was utilized to both characterize and justify the releasing behavior of the crosslinked systems. Comprehensive literature comparison between different analytical methods has been reviewed.


Assuntos
Antibacterianos/administração & dosagem , Cloranfenicol/administração & dosagem , Hidrogéis/química , Espectrofotometria Ultravioleta/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Sistemas de Liberação de Medicamentos
4.
J Clin Rheumatol ; 13(4): 199-201, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17762453

RESUMO

BACKGROUND: Fibromyalgia syndrome (FMS) usually affects women of working age. We expect significant work-related disability in association with FMS. Because of the variety of symptoms, these patients often have multiple visits to their general practitioners with many referrals and visits to various specialists. OBJECTIVE: To investigate the impact of fibromyalgia on working disability and health system utilization. METHOD: This was a case-control study comparing fibromyalgia outpatient attendees with controls attending nonrheumatology outpatient clinics in Eastern Scotland. One hundred thirty-six patients with FMS and 152 age- and sex-matched controls completed a postal questionnaire about their working history and attendance at various outpatient clinics and general practitioners' visits. RESULTS: Significant number of patients with FMS (46.8%) reported that they lost their job because of the disease, compared with only 14.1% of controls (P < 0.00001). There was no significant difference in health system utilization between patients with FMS and other clinic controls in a subset of patients surveyed. CONCLUSION: Fibromyalgia is significantly associated with reports of working disability. Reasons for this decreased employment need to be investigated. The impact on the health system appeared to be the same as for patients with known specific organic diseases with regard to the number of general practitioner or hospital visits.


Assuntos
Emprego/estatística & dados numéricos , Fibromialgia/epidemiologia , Serviços de Saúde/estatística & dados numéricos , Adulto , Estudos de Casos e Controles , Pessoas com Deficiência/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Inquéritos e Questionários
6.
Rheumatology (Oxford) ; 42(10): 1202-6, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12810939

RESUMO

OBJECTIVES: To determine whether women with fibromyalgia are at increased risk of developing osteoporosis or osteomalacia. METHODS: Forty premenopausal women with fibromyalgia and 37 age-matched female controls were studied. Broadband ultrasound attenuation (BUA) and velocity of sound (VOS) were measured at the calcaneum and bone mineral density was measured at the forearm and lumbar spine using dual-energy X-ray absorptiometry. Serum calcium, alkaline phosphatase, gamma-glutamyl transferase, 25-hydroxyvitamin D and plasma viscosity were measured in all subjects and parathyroid hormone was measured in subjects recruited in the latter part of the study. RESULTS: Seventeen patients with fibromyalgia syndrome and seven controls had 25-hydroxyvitamin D concentrations <20 nmol/l (P < 0.015) and in three FMS patients serum parathyroid hormone was raised. Bone density in fibromyalgia patients was slightly lower at the mid-distal forearm but comparable to that in controls at other sites. CONCLUSIONS: There is no reason to recommend routine bone densitometry in fibromyalgia patients. However, vitamin D subnutrition is common in these patients and this should be sought.


Assuntos
Fibromialgia/complicações , Osteoporose/etiologia , Vitamina D/análogos & derivados , Absorciometria de Fóton , Adulto , Densidade Óssea , Estudos de Casos e Controles , Feminino , Fibromialgia/sangue , Fibromialgia/fisiopatologia , Humanos , Pessoa de Meia-Idade , Osteomalacia/etiologia , Pré-Menopausa/sangue , Pré-Menopausa/fisiologia , Vitamina D/sangue
8.
Clin Rheumatol ; 21(6): 472-7, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12447630

RESUMO

The aim of this study was to ascertain whether fibromyalgia patients with positive ANA develop other features of connective tissue disease over 2-4 years' follow-up. Patients attending our clinic with a diagnosis of fibromyalgia were identified. All ANA-positive patients (n = 12) were recruited and matched for age and sex with 12 ANA-negative FMS patients. As further control groups, patients with a diagnosis of osteoarthritis (OA) were included. A screening questionnaire for possible features of connective tissue disease was sent to all participants. Patients who had three or more positive criteria were invited for further assessment. The ANA-positive rate was 12/137 (8.8%) in FMS and 20/225 (8.9%) in OA patients. All ANA positivity was at a low titre. Fourteen out of 20 (70%) FMS patients and 17/30 (56.7%) OA patients had three or more criteria (P = 0.34). No significant differences in the number of the positive criteria were found between those who were ANA positive or negative in both groups. On full assessment we found one patient who fulfilled the criteria for SLE from the ANA-positive FMS group and one in the ANA-negative group who fulfilled the criteria for primary Sjögren's syndrome. Of the patients with OA, one who was ANA positive was diagnosed as having rheumatoid arthritis. The results from our study show that ANA (at least in low titre) is not a good predictor of the future development of connective tissue.


Assuntos
Anticorpos Antinucleares/sangue , Doenças do Tecido Conjuntivo/imunologia , Fibromialgia/imunologia , Idoso , Doenças do Tecido Conjuntivo/complicações , Feminino , Fibromialgia/classificação , Fibromialgia/complicações , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/complicações , Osteoartrite/imunologia , Valor Preditivo dos Testes , Inquéritos e Questionários
9.
Rheumatology (Oxford) ; 41(4): 450-3, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11961177

RESUMO

OBJECTIVE: To investigate whether physical trauma may precipitate the onset of fibromyalgia syndrome (FMS). DESIGN: A case-control study was carried out to compare fibromyalgia out-patients with controls attending non-rheumatology out-patient clinics. METHOD: One hundred and thirty-six FMS patients and 152 age- and sex-matched controls completed a postal questionnaire about any physical trauma in the 6 months before the onset of their symptoms. RESULTS: Fifty-three (39%) FMS patients reported significant physical trauma in the 6 months before the onset of their disease, compared with only 36 (24%) of controls (P<0.007). There was no significant difference between FMS patients who had a history of physical trauma and those who did not have physical trauma with regard to age, sex, disease duration, employment status and whether their job at onset was manual. CONCLUSION: Physical trauma in the preceding 6 months is significantly associated with the onset of FMS.


Assuntos
Acidentes de Trabalho , Fibromialgia/etiologia , Ferimentos e Lesões/complicações , Estudos de Casos e Controles , Feminino , Fibromialgia/epidemiologia , Fibromialgia/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Inquéritos e Questionários , Reino Unido/epidemiologia , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/fisiopatologia
10.
Rheumatology (Oxford) ; 40(10): 1097-101, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11600737

RESUMO

OBJECTIVES: To assess microvascular activity in the skin of patients with fibromyalgia syndrome (FMS) as compared with normal controls. METHODS: Fifteen patients, who fulfilled the American College of Rheumatology criteria for FMS, and 15 age- and sex-matched healthy controls, were studied. The microvascular activity of the skin overlying the trapezius muscle was quantified using iontophoresis of acetylcholine as an endothelial-dependent vasodilator and sodium nitroprusside as an endothelial-independent vasodilator. We also studied the flare response by iontophoresing acetylcholine continuously for 10 min to stimulate a ring of nociceptor c-fibre endings in the skin. RESULTS: There was no significant difference in cutaneous vascular responses to short-duration iontophoresis of acetylcholine and sodium nitroprusside at the three different doses used. The area under the curve (AUC) (mean+/-s.e.m.) for acetylcholine baseline, 20, 40, and 80 s were 6+/-0.7, 23+/-6, 45+/-7 and 66+/-10 AU for patients and 11+/-4, 24+/-3, 49+/-7 and 62+/-12 AU for controls, respectively (P=0.2, 0.9, 0.7, 0.8, respectively). The corresponding figures for sodium nitroprusside were 5+/-1, 18+/-7, 51+/-14 and 68+/-14 AU for patients and 8+/-3, 13+/-2, 39+/-5 and 61+/-9 AU for controls, respectively (P=0.2, 0.5, 0.4, 0.7, respectively). There was also no significant difference in the flare response in patients with FMS as compared with control subjects (119+/-15 and 131+/-13 AU, respectively; P=0.57). CONCLUSION: There are no significant differences in cutaneous microvascular reactivity between patients with FMS and control subjects.


Assuntos
Fibromialgia/fisiopatologia , Pele/irrigação sanguínea , Acetilcolina , Adulto , Feminino , Humanos , Iontoforese , Masculino , Microcirculação/fisiologia , Pessoa de Meia-Idade , Fibras Nervosas/fisiologia , Nitroprussiato , Nociceptores/efeitos dos fármacos , Nociceptores/fisiologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fluxo Sanguíneo Regional/fisiologia , Pele/inervação , Vasodilatadores
11.
Rheumatology (Oxford) ; 40(3): 262-6, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11285372

RESUMO

OBJECTIVE: To investigate whether physical trauma may precipitate the onset of rheumatoid arthritis (RA). METHOD: In a case-control study comparing RA out-patients with controls attending non-rheumatology out-patient clinics, 262 patients and 262 age- and sex-matched controls completed a postal questionnaire or were interviewed about any physical trauma in the 6 months before the onset of their symptoms. RESULTS: Fifty-five (21%) of the RA patients reported significant physical trauma in the 6 months before the onset of their disease, compared with only 17 (6.5%) of the controls (P<0.00001). A preceding history of physical trauma was significantly more common in RA patients who were seronegative for rheumatoid factor (P=0.03), but was not significantly associated with sex (P=0.78), age (P=0.64), a family history of RA (P=0.07) or type of occupation, defined as manual or sedentary (P=0.6). CONCLUSION: Physical trauma in the preceding 6 months is significantly associated with the onset of RA.


Assuntos
Artrite Reumatoide/etiologia , Artrite Reumatoide/fisiopatologia , Ferimentos e Lesões/complicações , Ferimentos e Lesões/fisiopatologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estatística como Assunto , Inquéritos e Questionários , Fatores de Tempo
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 56A(10): 1971-7, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10989889

RESUMO

Antimony oxide trihalides, SbOX3 molecules, where X = F or Cl have been produced, by means of an on-line process, using antimony trichloride, SbOCl3 as starting material passed over heated silver oxide at 230 degrees C. The antimony oxide trichloride SbOCl3 formed is then reacted with sodium fluoride, NaF at 550 degrees C to produce antimony oxide trifluoride, SbOF3. The products have been characterized by the IR spectra of their vapors. Low resolution gas-phase Fourier transform infrared spectra show strong bands centered at 1272 and 1217 cm(-1), assigned to nu1(a1), the O=Sb stretching fundamental of SbOF3 and SbOCl3, respectively. Both observed bands show typical PQR-type structure with a strong Q-head.


Assuntos
Antimônio/análise , Óxidos/análise , Espectrofotometria Infravermelho/métodos , Antimônio/química , Óxidos/síntese química , Óxidos/química
13.
Scand J Rheumatol ; 29(2): 133-5, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10777130

RESUMO

Case 1. A 20-year-old woman presented 4 weeks post-partum with widespread symmetrical inflammatory polyarthropathy with marked synovitis. Investigations revealed grossly raised CRP with negative immunology screen. A few days before presentation she saw her general practitioner with left-sided mastitis, which then developed into a Staphylococcus breast abscess. Surgical drainage of this led to almost immediate resolution of the joint complaints and return of CRP to normal. Case 2. A 27-year-old man developed widespread symmetrical inflammatory arthropathy. A few days prior to this he had developed folliculitis with a furuncle on his neck. Swab grew Staphylococcus aureus. His arthritis settled immediately following spontaneous drainage of his abscess and a full course of antibiotic. The pathogenic mechanism is unclear but could be toxin-mediated.


Assuntos
Abscesso/complicações , Artrite/complicações , Infecções Estafilocócicas/complicações , Abscesso/microbiologia , Doença Aguda , Adulto , Feminino , Humanos , Masculino , Staphylococcus aureus
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 56(14): 2693-8, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11145335

RESUMO

A new route has been devised, leading to the production of VOX3 molecules where X=F, Br and I by an on-line process using vanadium oxytrichloride, VOCl3 as a starting compound passed over the following heated salts NaF, KBr and KI at 375, 700 and 550 degrees C, respectively. The products have been characterized by the IR spectra of their vapors. The low resolution gas phase on-line Fourier transform infrared spectra reported for the first time show strong bands with PQR type structure, centered at 1058, 1035, 1030 and 1025 cm(-1) assigned to the v1(a1), the O=V stretching fundamental mode of VOF3, VOCl3 VOBr3 and VOI3, respectively.


Assuntos
Óxidos/síntese química , Compostos de Vanádio/síntese química , Óxidos/química , Espectrofotometria Infravermelho/métodos , Vanádio/química , Compostos de Vanádio/química , Compostos de Vanádio/isolamento & purificação
15.
Clin Exp Rheumatol ; 16(4): 451-3, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9706426

RESUMO

OBJECTIVE: To study the outcome of osteoporosis assessment and rehabilitation in post-fracture patients. METHODS: This was a retrospective survey of the records of patients who had been referred to us from orthopaedic departments for rehabilitation after a fracture. RESULTS: A significant number of patients had had previous fractures (n = 17) or risk factors for osteoporosis (n = 16). The mortality rate was 4%. A significant proportion of patients (9/44) who had been living in their homes required placement in residential or nursing homes and additional care after rehabilitation. CONCLUSION: Our audit showed that post-fracture patients received optimum care, as set out in the Royal College of Physicians guidelines, but could benefit additionally from assessment and treatment of osteoporosis as set out in the Department of Health (DOH) Guidelines.


Assuntos
Fraturas Ósseas/reabilitação , Auditoria Médica , Osteoporose/diagnóstico , Osteoporose/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Avaliação Geriátrica , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Reino Unido
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA