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1.
Int J Clin Exp Med ; 8(11): 21335-42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26885074

RESUMO

This study aimed to compare the effects of cabbage compression early breast care (CCEBC) and early breast care (EBC) on breast pain, breast hardness with general nursing breast care (GNBC) in primiparous women after cesarean birth. Sixty participants were divided to three groups including CCEBC, EBC and GNBC. Each group was treated with its intervention respectively more than 10 minutes before breast feeding from day two to day four after delivery. The primary outcomes were breast pain and breast hardness. Both CCEBC and EBC showed significantly lower pain level than GNBC at day 4 after delivery. There are significant differences of breast hardness among three groups. CCEBC group showed significantly lower breast hardness compared with EBC and GNBC. Neither core body temperature nor breast skin temperature was significantly different among the three groups. In conclusion, CCEBC may effective in relieving breast pain and breast hardness compared with EBC alone and GNBC in primiparous women after a cesarean birth.

2.
Bioresour Technol ; 160: 203-12, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24565873

RESUMO

Biosorption is a promising technology not only for the removal of heavy metals and dyes but also for the recovery of precious metals (PMs) from solution phases. The biosorptive recovery of PMs from waste solutions and secondary resources is recently getting paid attractive attention because their price is increasing or fluctuating, their available deposit is limited and maldistributed, and high-tech industries need more consumption of PMs. The biosorbents for recovery of PMs require specifications which differ from those for the treatment of wastewaters containing heavy metals and dyes. In this review, the previous works on biosorbents and biosorption for recovery of PMs were summarized. Especially, we discuss and suggest the required specifications of biosorbents for recovery of PMs and strategies to give the required properties to the biosorbents. We believe this review will provide useful information to scientists and engineers and hope to give insights into this research frontier.


Assuntos
Biomassa , Metais/isolamento & purificação , Adsorção , Cinética
3.
J Hazard Mater ; 263 Pt 2: 391-7, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24225583

RESUMO

This work reports a novel concept for the development of a polysulfone (PS)-based fiber as a high-performance acid-tolerant adsorbent for the recovery of platinum group metals (PGMs), particularly Pt(IV), in acidic media. Polyethylenimine (PEI)-coated PS-Escherichia coli biomass composite fiber (PEI-PSBF) was prepared by spinning biomass-PS blends in water, coating with PEI and cross-linking with glutaraldehyde. The E. coli biomass on the fiber was executed as a functional group donor for binding PEI. PS fiber (PSF), PS-biomass composite fiber (PSBF), and PEI-modified PSF (PEI-PSF) were also prepared and compared with PEI-PSBF. The results of SEM and FTIR analyses revealed the presence of PEI on the surface of PEI-PSBF. Kinetic and isotherm experiments showed the negligible sorption capacity of PSF. In contrast, adsorption equilibrium on PSBF and PEI-PSBF was attained after 40 min and 6h, respectively. The maximum Pt(IV) uptake of PEI-PSBF was 6.6 times higher than that of PSBF. Pt(IV) ions were completely recovered from loaded PEI-PSBF by 0.1M thiourea in 1M HCl solution. The PEI-PSBF was also stable in 0.1M and 1M HCl solutions. The PEI-PSBF exhibited promising properties as an adsorbent for PGMs-containing acidic wastewaters.


Assuntos
Biodegradação Ambiental , Platina/química , Polímeros/química , Sulfonas/química , Tioureia/química , Poluentes Químicos da Água/análise , Ácidos , Adsorção , Biomassa , Reagentes de Ligações Cruzadas , Escherichia coli , Glutaral/química , Íons , Cinética , Metais , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície
4.
Bioresour Technol ; 137: 400-3, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23611701

RESUMO

This work reports a direct way to recover metallic palladium with high purity from Pd(II)-sorbed polyethylenimine-modified Corynebacterium glutamicum biosorbent using a combined method of biosorption and incineration. This study is focused on the incineration part which affects the purity of recovered Pd. The incineration temperature and the amount of Pd loaded on the biosorbent were considered as major factors in the incineration process, and their effects were examined. The results showed that both factors significantly affected the enhancement of the recovery efficiency and purity of the recovered Pd. SEM-EDX and XRD analyses were used to confirm that Pd phase existed in the ash. As a result, the recovered Pd was changed from PdO to zero-valent Pd as the incineration temperature was increased from 600 to 900°C. Almost 100% pure metallic Pd was recovered with recovery efficiency above 99.0% under the conditions of 900°C and 136.9 mg/g.


Assuntos
Corynebacterium glutamicum/metabolismo , Incineração/métodos , Paládio/química , Adsorção , Microscopia Eletrônica de Varredura , Paládio/metabolismo , Polietilenoimina/química , Temperatura
5.
Proteins ; 81(9): 1499-508, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23483653

RESUMO

The nitrogen-related phosphoenolpyruvate phosphotransferase system (PTS(Ntr) ) is involved in controlling ammonia assimilation and nitrogen fixation. The additional role of PTS(Ntr) as a regulatory link between nitrogen and carbon utilization in Escherichia coli is assumed to be closely related to molecular functions of IIA(Ntr) in potassium homeostasis. We have determined the crystal structure of IIA(Ntr) from Burkholderia pseudomallei (BpIIA(Ntr) ), which is a causative agent of melioidosis. The crystal structure of dimeric BpIIA(Ntr) determined at 3.0 Å revealed that its active sites are mutually blocked. This dimeric state is stabilized by charge and weak hydrophobic interactions. Overall monomeric structure and the active site residues, Arg51 and His67, of BpIIA(Ntr) are well conserved with those of IIA(Ntr) enzymes from E. coli and Neisseria meningitides. Interestingly, His113 of BpIIA(Ntr) , which corresponds to a key residue in another phosphoryl group relay in the mannitol-specific enzyme EIIA family (EIIA(Mtl) ), is located away from the active site due to the loop connecting ß5 and α3. Combined with other differences in molecular surface properties, these structural signatures distinguish the IIA(Ntr) family from the EIIA(Mtl) family. Since, there is no gene for NPr in the chromosome of B. pseudomallei, modeling and docking studies of the BpIIA(Ntr) -BpHPr complex has been performed to support the proposal on the NPr-like activity of BpHPr. A potential dual role of BpHPr as a nonspecific phosphocarrier protein interacting with both sugar EIIAs and IIA(Ntr) in B. pseudomallei has been discussed.


Assuntos
Proteínas de Bactérias/química , Burkholderia pseudomallei/enzimologia , Simulação de Acoplamento Molecular , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/química , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Burkholderia pseudomallei/genética , Cristalografia por Raios X , Dados de Sequência Molecular , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/genética , Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/metabolismo , Ligação Proteica , Alinhamento de Sequência
6.
Acta Crystallogr D Biol Crystallogr ; 69(Pt 4): 658-68, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23519675

RESUMO

ADP-L-glycero-D-manno-heptose 6-epimerase (AGME), the product of the rfaD gene, is the last enzyme in the heptose-biosynthesis pathway; it converts ADP-D-glycero-D-manno-heptose (ADP-D,D-Hep) to ADP-L-glycero-D-manno-heptose (ADP-L,D-Hep). AGME contains a catalytic triad involved in catalyzing hydride transfer with the aid of NADP(+). Defective lipopolysaccharide is found in bacterial mutants lacking this gene. Therefore, it is an interesting target enzyme for a novel epimerase inhibitor for use as a co-therapy with antibiotics. The crystal structure of AGME from Burkholderia thailandensis (BtAGME), a surrogate organism for studying the pathogenicity of melioidosis caused by B. pseudomallei, has been determined. The crystal structure determined with co-purified NADP(+) revealed common as well as unique structural properties of the AGME family when compared with UDP-galactose 4-epimerase homologues. They form a similar architecture with conserved catalytic residues. Nevertheless, there are differences in the substrate- and cofactor-binding cavities and the oligomerization domains. Structural comparison of BtAGME with AGME from Escherichia coli indicates that they may recognize their substrate in a `lock-and-key' fashion. Unique structural features of BtAGME are found in two regions. The first region is the loop between ß8 and ß9, affecting the binding affinity of BtAGME for the ADP moiety of ADP-D,D-Hep. The second region is helix α8, which induces decamerization at low pH that is not found in other AGMEs. With the E210G mutant, it was observed that the resistance of the wild type to acid-induced denaturation is related to the decameric state. An in silico study was performed using the Surflex-Dock GeomX module of the SYBYL-X 1.3 software to predict the catalytic mechanism of BtAGME with its substrate, ADP-D,D-Hep. In the in silico study, the C7'' hydroxymethyl group of ADP-D,D-Hep is predicted to form hydrogen bonds to Ser116 and Gln293. With the aid of these interactions, the hydroxyl of Tyr139 forms a hydrogen bond to O6″ of ADP-D,D-Hep and the proton at C6″ orients closely to C4 of NADP(+). Therefore, the in silico study supports a one-base mechanism as a major catalytic pathway, in which Tyr139 solely functions as a catalytic acid/base residue. These results provide a new insight into the development of an epimerase inhibitor as an antibiotic adjuvant against melioidosis.


Assuntos
Burkholderia/enzimologia , Carboidratos Epimerases/química , Carboidratos Epimerases/metabolismo , Adjuvantes Farmacêuticos/química , Adjuvantes Farmacêuticos/uso terapêutico , Animais , Carboidratos Epimerases/antagonistas & inibidores , Domínio Catalítico , Cristalografia por Raios X , Inibidores Enzimáticos/química , Inibidores Enzimáticos/uso terapêutico , Proteínas de Escherichia coli/antagonistas & inibidores , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Humanos , Melioidose/tratamento farmacológico , Melioidose/enzimologia , Melioidose/microbiologia , Ligação Proteica , Relação Estrutura-Atividade , Especificidade por Substrato
7.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 68(Pt 12): 1554-6, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23192046

RESUMO

TktA is the most critical enzyme in the nonoxidative pentose phosphate pathway. It catalyzes the conversion of xylulose 5-phosphate and ribose 5-phosphate into sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate, and its products are used in the biosynthesis of acetyl-CoA, aromatic amino acids, nucleic acids and ADP-L-glycero-ß-D-manno-heptose. TktA also has an unexpected role in chromosome structure that is independent of its metabolic responsibilities. Therefore, it is a new potent antibiotic target. In this study, TktA from Burkholderia pseudomallei has been cloned, expressed, purified and crystallized. Synchrotron X-ray data were also collected to 2.0 Šresolution. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a=146.2, b=74.6, c=61.6 Å, ß=113.0°. A full structural determination is under way in order to provide insight into the structure-function relationship of this protein.


Assuntos
Burkholderia pseudomallei/enzimologia , Transcetolase/química , Burkholderia pseudomallei/metabolismo , Cristalografia por Raios X , Relação Estrutura-Atividade , Fosfatos Açúcares/química , Fosfatos Açúcares/metabolismo , Transcetolase/metabolismo
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