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1.
Adv Colloid Interface Sci ; 277: 102119, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32045722

RESUMO

Emulsions, including oil-in-water (O/W) and water-in-oil (W/O) emulsions, can play important roles in both controlling reservoir conformance and displacing residual oil for enhanced oil recovery (EOR) projects. However, current methods, like high-shear mixing, high-pressure homogenizing, sonicators and others, often use lots of extra energy to prepare the emulsions with high costs but very low energy efficiency. In recent decades, spontaneous emulsification methods, which allow one to create micro- and nano-droplets with very low or even no mechanical energy input, have been launched as an overall less expensive and more efficient alternatives to current high extra energy methods. Herein, we primarily review the basic concepts on spontaneous emulsification, including mechanisms, methods and influenced parameters, which are relevant for fundamental applications for industrials. The spontaneity of the emulsification process is influenced by the following variables: surfactant structure, concentration and initial location, oil phase composition, addition of co-surfactant and non-aqueous solvent, as well as salinity and temperature. Then, we focus on the description of importance for emulsions in EOR processes from advances and categories to improving oil recovery mechanisms, including both sweep efficiency and displacement efficiency aspects. Finally, we systematically address the applications and outlooks based on the use of spontaneous emulsification in the practical oil reservoirs for EOR processes, in which conventional, heavy, high-temperature, high-salinity and low-permeability oil reservoirs, as well as wastewater treatments after EOR processes are involved.

2.
Trop Med Int Health ; 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31802572

RESUMO

OBJECTIVE: Tuberculosis (TB) treatment success rates are high in China, but there are still a considerable number of cases who have unfavourable treatment outcomes (UTO). We aimed to determine the proportion of TB patients with UTO and to assess whether baseline characteristics that included glycaemic status [normal fasting blood glucose (FBG), transient hyperglycaemia and diabetes mellitus (DM)] and vitamin D status were associated with UTO. METHOD: Prospective cohort study conducted between November 2015 and July 2016 at six clinics within routine TB services in Jilin province, where persons with TB were consecutively recruited. Data analysis was performed using the chi-squared test and multivariate logistic regression. RESULTS: Of the 306 recruited TB patients, 96 (31.4%) had smear-positive pulmonary TB, 187 (61.1%) had smear-negative pulmonary TB and 23 (7.5%) had extrapulmonary TB (EPTB). Of these, 95 (31.1%) had normal blood glucose, 83 (27.1%) had transient hyperglycaemia and 128 (41.8%) had DM. 227 (74.2%) patients had vitamin D deficiency/severe deficiency. There were 125 (40.8%) patients with UTO of whom the majority were lost to follow-up (57.6%) or not evaluated (28.8%). UTO was significantly associated with smear-negative pulmonary TB (P = 0.009), EPTB (P < 0.001) and DM (P = 0.007). CONCLUSION: The proportion of TB patients with UTO increased with smear-negative pulmonary TB, EPTB and DM. TB programmes need to pay more attention to these issues and ensure intensive patient support to those at risk and early detection of DM.

3.
Soft Matter ; 15(12): 2703-2710, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30816889

RESUMO

A dynamic covalent bond is widely used to fabricate stimuli responsive systems due to its reversible molecular recognition properties. In this study, we developed a pH-responsive morphology transition system based on a mixture of a cationic surfactant CTAB and two nonamphiphilic precursors, 4-hydroxybenzaldehyde (HB) and octylamine (OA), at a molar ratio of 100 : 60 : 60 (CTAB/HB/OA). The morphology transition of CTAB/HB/OA was characterized by 1H NMR spectroscopy, Fourier transform infrared spectroscopy, macroscopic appearance observation, dynamic light scattering, and rheological and cryo-TEM measurements. The phase behavior of CTAB/HB/OA solutions underwent transition from a water-like fluid to a transparent gel-like solution and then converted into a turbid low-viscosity solution upon increasing the pH. Upon increasing the pH from 4.93 to 7.99, the morphology was transformed from spherical micelles to wormlike micelles. Upon further increasing the pH to 12.02, the wormlike micelles gradually disappeared with the formation of vesicles. Thus, a morphology transition from micelles to vesicles can be triggered by varying the pH of CTAB/HB/OA solutions. This drastic variation in morphology behavior was attributed to the pH dependent ionization and formation of the anionic surfactant HB-OA-. Besides, over 3 cycles of morphological alternation among spherical micelles, wormlike micelles and vesicles of the CTAB/HB/OA solutions can be obtained by adjusting the pH.

4.
Soft Matter ; 15(15): 3160-3167, 2019 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-30865762

RESUMO

A worm-like micelle (WLM) system can be obtained by mixing long-chain cationic surfactants and polybasic organic acids in an aqueous solution. However, the effect of different organic acid structures on the rheological behavior of WLM systems has not been researched. Herein, a novel pH-responsive wormlike micelle system (EATA) was constructed by the complexation of N-erucamidopropyl-N,N-dimethylamine (UC22AMPM) and benzene tricarboxylic acid (TA) at a molar ratio of 3 : 1. UC22AMPM/citric acid (EACA) was also prepared to perform a comparison. The rheological behavior, aggregate transformation and thickening mechanism of EATA solutions were investigated by using rheological measurements, cryo-TEM, DLS, surface tension and 1H NMR. The results show that, at low pH, spherical micelles were formed and the EATA solution exhibited a lower viscosity than the EACA system due to the strong hydrophobicity of the phenyl groups of TA molecules, but the viscosity reaches 106 mP s at pH 4.80. Because of the lower pKa value of TA than CA, the viscosity of the EATA system drops sharply with the appearance of precipitates caused by the isoelectric point when the pH is greater than 4.80. In addition, by circularly changing the pH value several times, the wormlike micelles could maintain their original viscoelasticity without being weakened in the slightest.

5.
PLoS One ; 13(11): e0206372, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30383776

RESUMO

BACKGROUND: Vitamin D could be a mediator in the association between tuberculosis (TB) and diabetes mellitus (DM). A large scale multi-center study confirmed that TB patients with DM had significantly lower serum vitamin D level compared with those without DM and reported that DM was a strong independent risk factor for vitamin D deficiency. OBJECTIVES: This study was undertaken to determine amongst patients with both TB and DM living in different economically defined areas in China: i) their baseline characteristics, ii) their vitamin D status and iii) whether certain baseline characteristics were associated with vitamin D deficiency. METHODS: In DM-TB patients consecutively attending seven clinics or hospitals, we measured 25 hydroxycholecalciferol at the time of registration using electrochemiluminescence in a COBASE 601 Roche analyser by chemiluminescence immunoassay. Data analysis was performed using chi square test and multivariate logistic regression. RESULTS: There were 178 DM-TB patients that included 50 from economically well-developed areas, 103 from better-off areas and 25 from a poverty area. Median vitamin D levels in well-developed, better-off and poverty areas were 11.5ng/ml, 12.2ng/ml and 11.5ng/ml respectively. Amongst all patients, 149 (84%) had vitamin D deficiency-91 (51%) with vitamin D deficiency (10-19.9 ng/ml) and 58 (33%) with severe deficiency (< 10 ng/ml). There was a significantly higher proportion with vitamin D deficiency in the poverty area. The adjusted odds of vitamin D deficiency (25-(OH)D3 <20 ng/ml) were significantly higher in those with longer history of DM (P = 0.038) and with HbA1c≥10% (P = 0.003). CONCLUSION: Over 80% of TB patients with DM in China were vitamin D deficient, with risk factors being residence in a poverty area, a long duration of DM and uncontrolled DM. TB programme managers and clinicians need to pay more attention to the vitamin D status of their patients.


Assuntos
Diabetes Mellitus/sangue , Diabetes Mellitus/epidemiologia , Status Econômico/estatística & dados numéricos , Tuberculose/sangue , Tuberculose/epidemiologia , Vitamina D/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Estudos Transversais , Complicações do Diabetes/sangue , Complicações do Diabetes/epidemiologia , Diabetes Mellitus/economia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Áreas de Pobreza , Fatores de Risco , Classe Social , Tuberculose/complicações , Tuberculose/economia , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/economia , Deficiência de Vitamina D/epidemiologia
6.
Soft Matter ; 14(24): 5031-5038, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29862407

RESUMO

Responsive wormlike micelles are very useful in a number of applications, whereas it is still challenging to create dramatic viscosity changes in anionic surfactant systems. Here a differential pH-responsive wormlike micelle based on sulfonic surfactants was developed, which is formed by mixing sodium dodecyl trioxyethylene sulphate (SDES) and ethylenediaminetetraacetic acid tetrasodium (EDTA4-·4Na+) at the molar ratio of 1 : 1. The phase behavior, aggregate microstructure and viscoelasticity of the SDES/EDTA4-·4Na+ solution were investigated via macroscopic observation, cryo-TEM and rheological measurements. It was found that the phase behavior of the SDES/EDTA4-·4Na+ solution undergoes transitions from a water-like fluid to viscoelastic upon decreasing the pH. On decreasing the pH from 12.01 to 3.27 by adding HCl, the viscosity of the transparent solutions with wormlike micelles was increased rapidly and reached ∼3100 mPa s. Furthermore, on increasing the pH by adding NaOH, the viscosity was slightly increased due to the addition of Na+. However, the increase in the concentration of Na+ is much smaller than the theoretical addition. The same phenomenon was noted in the sodium citrate solution, but does not exist in the sodium formate system. The viscosity of the micellar solution has a sensitive response to inorganic acids and tolerance to inorganic bases due to the characteristics of polybasic acids.

7.
Soft Matter ; 14(22): 4445-4452, 2018 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-29693695

RESUMO

Responsive wormlike micelles (WLMs) constructed by different carboxylic acids are fascinating. However, it is unknown how the position of the carboxylic groups alters the stimuli-response of wormlike micellar systems. Herein, three pH-responsive WLMs based on Gemini-like surfactants (named o-EAPA, m-EAPA, and p-EAPA) were formed and studied through the complexation of N-erucamidopropyl-N,N-dimethylamine (UC22AMPM) and o-phthalic acid (o-PA), m-phthalic acid (m-PA), or p-phthalic acid (p-PA) at the molar ratio of 2 : 1. The viscoelasticity, phase behavior and aggregate microstructure were separately explored by rheological, appearance observation and cryo-TEM methods. The results show that all phthalic acids can protonate UC22AMPM, thereby forming WLMs. However, with the shorter spacer distance between two carboxyl groups in phthalic acid, o-EAPA exhibits the longer length scale of aggregates and a more efficient thickening ability compared to the other two systems. Similar results in the N,N-dimethyl oleoaminde-propylamine (DOAPA) and o-PA, m-PA, and p-PA systems further verify the applicability of this mechanism. Furthermore, the phthalic acid based WLMs are found to exhibit intriguing reversible pH-responsive behaviors, which include promptly switching between a high elastic system and a low viscosity fluid by pH control. The o-EAPA system possesses a larger viscosity maximum, which produces more precipitous viscosity changes as the pH varies. This study is beneficial for the formation of pH-responsive WLMs and to determine their advantages for applications.

8.
Sci Rep ; 8(1): 4236, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29523795

RESUMO

We compared the positive rates of T-SPOT.TB and bacterial culture in the smear-negative PTB, and analyzed the factors affecting the results of negative T-SPOT.TB and bacterial culture. Retrospective evaluation of data from smear-negative PTB patients who underwent T-SPOT.TB and bacterial culture were done. The agreement and concordance were analyzed between T-SPOT.TB and bacterial culture. Multivariable logistic regression analysis was used to explore the factors associated with positive results of T-SPOT.TB and bacterial culture in smear-negative PTB. 858 eligible smear-negative PTB patients were included in the study. The agreement rate was 25.6% (22.7~28.5%) between T-SPOT.TB and bacterial culture in smear- negative PTB patients. The positive rate of T-SPOT.TB was higher than that of bacterial culture in smear-negative PTB patients (p < 0.001). There were nearly no concordance between T-SPOT.TB and bacterial culture (p > 0.05). Using multivariable logistic regression analysis we found that older age ≥ 60 years (OR = 0.469, 95% CI: 0.287-0.768) and decreased albumin (OR = 0.614, 95% CI: 0.380-0.992) were associated with negative diagnostic results of T-SPOT.TB in smear-negative PTB patients. Female (OR = 0.654, 95% CI: 0.431-0.992) were associated with negative diagnostic results of bacteria culture in smear-negative PTB patients. Our results indicated that the older age and decreased albumin were independently associated with negative T-SPOT.TB responses.


Assuntos
Tuberculose Pulmonar/diagnóstico , China/epidemiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/fisiologia , Estudos Retrospectivos , Fatores de Risco , Escarro/microbiologia , Tuberculose Pulmonar/epidemiologia
9.
Bioresour Technol ; 259: 349-356, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29574315

RESUMO

The performance and de-emulsification mechanism of α-amylase, a novel environmental friendly biodemulsifier in petroleum industry, was investigated at room temperature. The effects of α-amylase on the viscosity of amphiphilic polymer solution and de-emulsification rate were studied by changing the concentration of α-amylase, temperature and salinity. Polymer molecular weight, Zeta potential, interfacial film strength and interfacial tension were measured to investigate the de-emulsification mechanism of α-amylase. The results show that α-amylase is an efficient biodemulsifier to increase the de-emulsification rate of amphiphilic polymer emulsions. Hydrolysis of α-amylase to amphiphilic polymers destroys the structure of the amphiphilic polymer, thereby reduces the viscosity and the interfacial film strength of the system. Once de-emulsification is completed, the lower layer, i.e. the emulsified layer, will be clear. Thus, α-amylase can be applied as an effective de-emulsifier for amphiphilic polymer-stabilized O/W emulsion.


Assuntos
Polímeros , alfa-Amilases , Emulsificantes , Emulsões , Viscosidade
10.
Chin Med J (Engl) ; 131(3): 268-275, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29363640

RESUMO

BACKGROUND: Interferon-gamma release assay (IGRA) has been used in latent tuberculosis (TB) infection and TB diagnosis, but the results from different high TB-endemic countries are different. The aim of this study was to investigate the value of IGRA in the diagnosis of active pulmonary TB (PTB) in China. METHODS: We conducted a large-scale retrospective multicenter investigation to further evaluate the role of IGRA in the diagnosis of active PTB in high TB-epidemic populations and the factors affecting the performance of the assay. All patients who underwent valid T-SPOT.TB assays from December 2012 to November 2015 in six large-scale specialized TB hospitals in China and met the study criteria were retrospectively evaluated. Patients were divided into three groups: Group 1, sputum culture-positive PTB patients, confirmed by positive Mycobacterium tuberculosis sputum culture; Group 2, sputum culture-negative PTB patients; and Group 3, non-TB respiratory diseases. The medical records of all patients were collected. Chi-square tests and Fisher's exact test were used to compare categorical data. Multivariable logistic analyses were performed to evaluate the relationship between the results of T-SPOT in TB patients and other factors. RESULTS: A total of 3082 patients for whom complete information was available were included in the investigation, including 905 sputum culture-positive PTB cases, 914 sputum culture-negative PTB cases, and 1263 non-TB respiratory disease cases. The positive rate of T-SPOT.TB was 93.3% in the culture-positive PTB group and 86.1% in the culture-negative PTB group. In the non-PTB group, the positive rate of T-SPOT.TB was 43.6%. The positive rate of T-SPOT.TB in the culture-positive PTB group was significantly higher than that in the culture-negative PTB group (χ2 = 25.118, P < 0.01), which in turn was significantly higher than that in the non-TB group (χ2 = 566.116, P < 0.01). The overall results were as follows: sensitivity, 89.7%; specificity, 56.37%; positive predictive value, 74.75%; negative predictive value, 79.11%; and accuracy, 76.02%. CONCLUSIONS: High false-positive rates of T-SPOT.TB assays in the non-TB group limit the usefulness as a single test to diagnose active TB in China. We highly recommend that IGRAs not be used for the diagnosis of active TB in high-burden TB settings.


Assuntos
Testes de Liberação de Interferon-gama/métodos , Tuberculose Pulmonar/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Interferon gama/análise , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Estudos Retrospectivos , Sensibilidade e Especificidade , Escarro/microbiologia , Adulto Jovem
11.
Carbohydr Polym ; 181: 224-233, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29253967

RESUMO

The stability and mechanism of O/W Pickering emulsions stabilized with regenerated cellulose were investigated. The Turbiscan Lab Expert Stabilizer, Particle Size Analyser, and Physica MCR301 Rheometer were used. When the concentration of regenerated cellulose increases, the aggregation of regenerated cellulose, emulsion stability and bulk and interfacial viscoelasticity increase as the diameter of the oil droplets decreases. In addition, the emulsions display a typical gel-like characteristic, and the oil-water interfacial shear rheological behaviour slightly differs from that of the O/W Pickering emulsions. This difference can be attributed to the aggregation of regenerated cellulose in the droplet surface under the shear condition. The emulsions exhibit excellent salt resistance at high salt concentrations. Moreover, the regenerated cellulose displays a better temperature resistance than amphiphilic polymer (AP), which is commonly used in oilfields. Hence, commercially available regenerated cellulose can be used as an ideal candidate for enhanced oil recovery.

12.
Soft Matter ; 13(40): 7425-7432, 2017 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-28967008

RESUMO

Wormlike micelles (WLMs) have been observed in a wide variety of cationic surfactants. Here we developed WLMs based on an N-allyl substituted cationic surfactant with an unsaturated C22-tail, N-erucamidopropyl-N,N-dimethyl-N-allyl-ammonium bromide (EDAA), and compared them with UC22AMPM at the same concentration. The viscoelasticity, aggregate microstructure and salt tolerance of EDAA solutions were investigated by rheology, surface tension and Cryo-TEM measurements. It was found that EDAA exhibited a higher viscosity and a high salt tolerance. Upon increasing the concentration of NaCl, the viscosity of wormlike micelles in the solutions continuously increased and reached ∼1.10 × 106 mP s at 200 mM. On further increasing the NaCl concentration to 2000 mM, the viscosity remained at ∼106 mP s without any reduction. But the viscosity of UC22AMPM solutions showed a drastic change with the increase of NaCl concentration. This drastic variation in rheological behavior is attributed to the presence of the N-allyl substituent. Besides, the EDAA also shows some advantages such as low overlapping concentration(∼2.2 mM) and stable viscosity over the whole pH range.

13.
BMJ Open ; 7(9): e017557, 2017 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-28951414

RESUMO

OBJECTIVE: The association between tuberculosis (TB), diabetes mellitus (DM) and vitamin D status is poorly characterised. We therefore: (1) determined vitamin D status in patients with TB in relation to whether they had normal fasting blood glucose (FBG), pre-DM or DM and (2) assessed whether baseline characteristics in patients with TB, including their DM status, were associated with vitamin D deficiency. METHODS: In patients with TB consecutively attending six clinics or hospitals in China, we measured 25-hydroxycholecalciferol (25-(OH)D3) at the time of registration using electrochemiluminescence in a COBASE 601 Roche analyser by chemiluminescence immunoassay. Data analysis was performed using the χ2 test, ORs and multivariate logistic regression. RESULTS: There were 306 eligible patients with TB, including 96 with smear positive pulmonary TB, 187 with smear negative pulmonary TB and 23 with extrapulmonary TB. Of these, 95 (31%) had normal blood glucose, 83 (27%) had pre-DM and 128 (42%) had DM. Median serum vitamin D levels were 16.1 ng/mL in patients with TB with normal FBG, 12.6 ng/mL in patients with TB with pre-DM and 12.1 ng/mL in patients with TB with DM (p<0.001). The study highlighted certain baseline characteristics associated with vitamin D deficiency (25-(OH)D3<20 ng/mL). After adjusting for confounders, serum vitamin D deficiency was significantly more common in patients being registered in the cold season (November to April) (p=0.006) and in those with DM (p=0.003). CONCLUSION: Vitamin D levels are lower in patients with TB with pre-DM and DM and are also affected by certain baseline characteristics that include being registered in the cold season and having DM. TB programmes need to pay more attention to vitamin D status in their patients, especially if there is coexisting pre-DM or DM.


Assuntos
Calcifediol/sangue , Diabetes Mellitus/sangue , Tuberculose Pulmonar/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Glicemia/metabolismo , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Áreas de Pobreza , Estado Pré-Diabético/sangue , Estado Pré-Diabético/complicações , Fatores de Risco , População Rural/estatística & dados numéricos , Tuberculose Pulmonar/complicações , População Urbana/estatística & dados numéricos , Adulto Jovem
14.
Glob Health Action ; 10(1): 1289737, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28470109

RESUMO

OBJECTIVE: We aimed to observe (i) changes in fasting blood glucose (FBG) in tuberculosis (TB) patients before and during anti-TB treatment, (ii) whether FBG levels were stable or unstable and (iii) baseline characteristics associated with an unstable FBG. METHOD: TB patients consecutively attended six clinics or hospitals. FBG measurements were made at months 0, 2 and 6. Data analysis was performed using the chi-square test and multivariate logistic regression. RESULTS: Of 232 patients without diabetes mellitus (DM) whose initial FBG < 6.1 mmol/L, over 90% maintained FBG < 6.1 mmol/L during treatment and no patient developed DM. Of 17 patients without DM and initial FBG between 6.1 and 6.9 mmol/L, over half had FBG < 6.1 mmol/L during treatment and no patient had DM at the end of treatment. Eight DM patients with already known DM had their FBG controlled at < 7.0 mmol/L during treatment. There were 13 DM patients newly diagnosed with FBG ≥ 7.0 mmol/L, and 69% continued to have FBG ≥ 7.0 mmol/L. After adjustment for confounding, the odds for an unstable FBG were higher for HIV-positive status, already having DM, smoking and coming to hospitals rather than clinics. CONCLUSION: TB patients who do not have DM based on FBG measurements do not develop DM during anti-TB treatment. Those newly diagnosed with DM on screening in general maintain their DM status with high FBG and need to be better managed.


Assuntos
Antituberculosos/uso terapêutico , Glicemia , Tuberculose/sangue , Tuberculose/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial , Antituberculosos/administração & dosagem , Criança , China , Jejum , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Tuberculose/diagnóstico , Adulto Jovem
15.
Soft Matter ; 13(6): 1182-1189, 2017 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-28098315

RESUMO

Responsive wormlike micelles are very useful in a number of applications, whereas it is still challenging to create dramatic viscosity changes in wormlike micellar systems. Here we developed a pH-responsive wormlike micellar system based on a noncovalent constructed surfactant, which is formed by the complexation of N-erucamidopropyl-N,N-dimethylamine (UC22AMPM) and citric acid at the molar ratio of 3 : 1 (EACA). The phase behavior, aggregate microstructure and viscoelasticity of EACA solutions were investigated by macroscopic appearance observation, rheological and cryo-TEM measurements. It was found that the phase behavior of EACA solutions undergoes transition from transparent viscoelastic fluids to opalescent solutions and then phase separation with white floaters upon increasing the pH. Upon increasing the pH from 2.03 to 6.17, the viscosity of wormlike micelles in the transparent solutions continuously increased and reached ∼683 000 mPa s at pH 6.17. As the pH was adjusted to 7.31, the opalescent solution shows a water-like flowing behaviour and the η0 rapidly declines to ∼1 mPa s. Thus, dramatic viscosity changes of about 6 magnitudes can be triggered by varying the pH values without any deterioration of the EACA system. This drastic variation in rheological behavior is attributed to the pH dependent interaction between UC22AMPM and citric acid. Furthermore, the dependence on concentration and temperature of the rheological behavior of EACA solutions was also studied to assist in obtaining the desired pH-responsive viscosity changes.

16.
Hum Vaccin Immunother ; 12(4): 960-70, 2016 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-27002369

RESUMO

Pediatric tuberculosis contributes significantly to the burden of TB disease worldwide. In order to achieve the goal of eliminating TB by 2050, an effective TB vaccine is urgently needed to prevent TB transmission in children. BCG vaccination can protect children from the severe types of TB such as TB meningitis and miliary TB, while its efficacy against pediatric pulmonary TB ranged from no protection to very high protection. In recent decades, multiple new vaccine candidates have been developed, and shown encouraging safety and immunogenicity in the preclinical experiments. However, the limited data on protective efficacy in infants evaluated by clinical trials has been disappointing, an example being MVA85A. To date, no vaccine has been shown to be clinically safer and more effective than the presently licensed BCG vaccine. Hence, before a new vaccine is developed with more promising efficacy, we must reconsider how to better use the current BCG vaccine to maximize its effectiveness in children.


Assuntos
Vacina BCG , Vacinas contra a Tuberculose , Tuberculose Pulmonar/prevenção & controle , Tuberculose/prevenção & controle , Vacina BCG/administração & dosagem , Vacina BCG/efeitos adversos , Vacina BCG/imunologia , Criança , Ensaios Clínicos como Assunto , Humanos , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/efeitos adversos , Vacinas contra a Tuberculose/imunologia , Tuberculose Pulmonar/imunologia , Vacinação
17.
Trop Med Int Health ; 20(8): 1073-80, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25877338

RESUMO

OBJECTIVE: To assess the feasibility and results of screening of patients with DM for TB in routine community health services in China. METHOD: Agreement on how to screen patients with DM for TB and monitor and record the results was obtained at a stakeholders meeting. Subsequent training was carried out for staff at 10 community health centres, with activities implemented from June 2013 to April 2014. Patients with DM were screened for TB at each clinical visit using a symptom-based enquiry, and those positive to any symptom were referred to the TB clinic for TB investigation. RESULTS: A total of 2942 patients with DM visited these ten clinics. All patients received at least one screening for TB. Two patients were identified as already known to have TB. In total, 278 (9.5% of those screened) who had positive TB symptoms were referred for TB investigations and 209 arrived at the TB centre or underwent a chest radiograph for TB investigation. One patient (0.5% of those investigated) was newly diagnosed with active TB and was started on anti-TB treatment. The TB case notification rate of those screened was 102/100,000. CONCLUSION: This pilot project shows it is feasible to carry out TB screening among patients with DM in community settings, but further work is needed to better characterise patients with DM at higher risk of TB. This may require a more targeted approach focused on high-risk groups such as those with untreated DM or poorly controlled hyperglycaemia.


Assuntos
Instituições de Assistência Ambulatorial , Serviços de Saúde Comunitária , Diabetes Mellitus Tipo 2/complicações , Programas de Rastreamento/métodos , Saúde Pública/métodos , Tuberculose Pulmonar/diagnóstico , Adulto , Idoso , China , Diabetes Mellitus , Feminino , Humanos , Hiperglicemia/complicações , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prevalência , Encaminhamento e Consulta , Tuberculose/complicações , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose Pulmonar/complicações , Tuberculose Pulmonar/epidemiologia
18.
Vaccine ; 33(1): 209-13, 2015 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-25454854

RESUMO

Bacille Calmette-Guérin (BCG) vaccine is still the most effective approach to prevent tuberculosis in childhood. In order to provide protection against severe forms of childhood tuberculosis, it is customary to give BCG vaccination at birth in China. Tuberculin skin testing after vaccination is usually used to evaluate the immunogenic activity and protective efficacy of the BCG. We report the results of a multi-site prospective cohort study to evaluate the immunological reactivity against BCG in four prefectural cities in China. A total of 59,022 newborn infants were vaccinated between January 2011 and March 2012, and follow-up data on 27,517 vaccinated infants were available for this study. Of these, 679 (2.5%) had PPD readings of 0-5mm, 17,072 (62.0%) had PPD readings of 5-10 mm of induration, 8864 (32.2%) had readings of 10-15 mm, 815 (3.0%) had readings of 15-20 mm, and 87 (0.3%) had readings of >20 mm of induration. The size of PPD reaction varied significantly with the geographic location, gender, season of vaccination, and grade of hospital administering the BCG vaccine (P<0.001). 97.8% of the infants with a BCG scar of >1mm had a positive TST reaction. However, only 56.9% of infants without a BCG scar had a positive PPD reaction. Our results demonstrate that the BCG immunization among newborn infants in China induces satisfactory immune response. In addition, BCG scars provide a useful indicator of vaccination response in Chinese infants.


Assuntos
Vacina BCG/administração & dosagem , Vacina BCG/imunologia , Teste Tuberculínico , Tuberculose/prevenção & controle , Vacinação/métodos , China , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos
19.
Soft Matter ; 10(25): 4506-12, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24817411

RESUMO

We report in this work the phase behavior and microstructures in a mixture of an anionic Gemini surfactant, sodium dilauramino cystine (SDLC), and a conventional cationic surfactant, dodecyl trimethyl ammonium chloride (DTAC). Observation of the appearance shows that the phase behavior of the SDLC-DTAC mixed cationic surfactant system transforms from an isotropic homogeneous phase to an aqueous surfactant two-phase system (ASTP) and then to an anisotropic homogeneous phase with the continuous addition of DTAC. The corresponding aggregate microstructures are investigated by rheology, dynamic light scattering, transmission electron microscopy and polarization microscopy. It has been found that a wormlike micelle, in the isotropic homogeneous phase, occurs linear to the branch growth. The aggregate microstructures in the ASTP lower and upper phases are branched wormlike micelles and vesicles, respectively. The micelle transformed into a vesicle upon varying the phase volume percentage until a lamellar liquid crystal formed in the anisotropic homogeneous phase. The macroscopic phase behavior and microscopic aggregate structure are related to the understanding of the possible mechanisms for the above phenomena.

20.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 5): m495, 2010 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-21578997

RESUMO

The mol-ecular structure of the title compound, [Sn(2)(C(10)H(13))(4)(C(14)H(20))Cl(2)], is a binuclear centrosymmetric complex, in which the Sn atoms are four-coordinated by three C atoms and one Cl atom in a distorted tetra-hedral geometry.

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