Search

In this work, graphene modified with sodium dodecyl sulfate was used to remove Fe (III) and Al (III) from wastewater. Morphological and spectrophotometrical characterization was done to confirm synthesis. Modified graphene performance was studied; pH effect, time of maximal sorption, maximal concentration of absorbent and concentration of ions were studied, as well. Sorption kinetic studies and isotherm models were applied to know the sorption process spontaneity and carried out to evaluate theoretical characteristic rates and possible adsorption mechanisms. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction studies revealed that graphene surface was successfully modified with sodium dodecyl sulfate, which also was confirmed by Fourier transform infrared spectroscopy. Optimal pH for removal of Al (III) and Fe (III) was 8. The time of maximal adsorption for both ions was 120 min, and the best dose of graphene modified with sodium dodecyl sulfate for their sorption was 0.1 g/L values for Fe (III) and Al (III), indicating that adsorption was favorable. 1/n values revealed cooperative adsorption. The model of adsorption of Fe (III) and Al (III) fits better to Langmuir than the Freundlich model. It was found that graphene modified with sodium dodecyl sulfate sorption’s kinetic model fits with pseudo-second order for Al (III) and Fe (III).

海绵状血管瘤是女性生殖道非常罕见的肿瘤，可能引起临床医师在诊断上的混淆，其诊断主要依靠组织病理学检查。该文报道了1例子宫内膜海绵状血管瘤性息肉，本例通过宫颈内口突入阴道，表现为宫颈息肉并引起阴道出血。本例提示宫颈病变可能并不一定来源于宫颈，病理医师和临床医师要多加注意，避免混淆和误诊。.

identification was made of a series of synthesized mono- and diacyl derivatives of diosgenyl saponins at various positions of the sugars. the complete assignments of h-1 and c-13 nmr spectral lines were achieved by careful analysis of their homo- and heteronuclear two-dimensional nmr spectra. copyright (c) 2002 john wiley sons, ltd.

Dioscin, polyphyllin D, and balanitin 7, which belong to a group of structurally similar diosgenyl saponins with promising bioactivities, were synthesized by stepwise glycosylation.

The complete assignments of 1H and 13C NMR data for a series of synthesized diosgenyl saponin analogs are described, viz. diosgenyl β-D-glucopyranoside (1), diosgenyl α-L-rhamnopyranosyl-(12)-β-D-glucopyranoside (2), diosgenyl α-L-rhamnopyranosyl-(13)-β-D-glucopyranoside (3), diosgenyl α-L-rhamnopyranosyl-(12)-α-L-rhamnopyranosyl-(13)-β-D-glucopyranoside (4), α-L-rhamnopyranosyl-(12)-β-D-xylopyranosyl-(13)-β-D-glucopyranoside (5), α-L-rhamnopyranosyl-(12)-β-L-arabinofuranosyl-(13)-β-D-glucopyranoside (6) and α-L-rhamnopyranosyl-(12)-β-D-glucopyranosyl-(13)-β-D-glucopyranoside (7). The assignments were achieved using homo- and heteronuclear two-dimensional NMR techniques. Copyright © 1999 John Wiley & Sons, Ltd.

The identification of six synthesized diosgenyl saponin analogs with up to five sugars was accomplished by nmr studies. a combination of homo- and heteronuclear two-dimensional nmr techniques was utilized to achieve the complete h-1 and c-13 nmr assignments. copyright (c) 2000 john wiley & sons, ltd.

Human papillomavirus (HPV) DNA has been identified in esophageal carcinomas. However, the incidence of HPV varies significantly in different geographic locations. In the current study, neoplasms from two separate geographic regions were analyzed for the presence of HPV DNA:One hundred and ten esophageal squamous cell carcinomas, 83 from Beijing, China and 27 from Cincinnati, Ohio, were examined for the presence of HPV DNA: In situ hybridization and polymerase chain reaction (PCR) using both consensus primers for the HPV L1 gene and type specific primers for the E6 gene of HPV types 6, 16, and 18 were performed.In situ hybridization failed to demonstrate any HPV type (6, 11, 16, 18, 31, 33, or 35) in any tumor specimen. Likewise, PCR using consensus primers for the HPV L1 gene was negative in all samples. Three of the Chinese specimens (4.29%) were positive for HPV using E6 type specific primers. One tumor contained HPV type 6 DNA, whereas the other 2 contained HPV type 16 DNA. One Cincinnati tumor (4.35%) was positive for HPV 16 by type specific primer. None of the specimens contained HPV 18 DNA.The incidence of HPV DNA in esophageal carcinoma specimens from Beijing, China and Cincinnati, Ohio is similar. The incidence of HPV in tumors from Beijing is significantly lower than that reported for those from other regions of China where the incidence of esophageal cancer is higher. Thus, although HPV may play a role in esophageal carcinogenesis, this role may be more pronounced in those regions of the world with a high incidence of the disease, and may be less important in areas with moderate or low risks for esophageal cancer.

Anogenital malignancy has been increasing in incidence in recent decades. There is strong evidence in the literature suggesting that human papillomavirus (HPV) plays a role in the genesis of anogenital neoplasia. In addition, identification of oncogenic HPV types in anogenital carcinomas may have prognostic significance. The method used to detect HPV infection, however, affects the frequency with which viral DNA is identified. We examined tissues from 56 patients with anal squamous cell carcinoma for the presence of HPV DNA by in situ hybridization and polymerase chain reaction using both consensus and type-specific primers to determine if HPV detection varies when different methods are used. In situ hybridization identified the presence of HPV DNA in 41.1% of patients. Polymerase chain reaction using type-specific probes for the HPV E6 gene demonstrated HPV DNA in 46% of anal carcinomas, whereas polymerase chain reaction with consensus primers detected HPV DNA in only 16.3% of cases. All cases containing HPV type 6 were identified with L1 primers, whereas only three of 23 cases containing HPV type 16 were identified. The differences in the rate of HPV detection by the two polymerase chain reactions methods are most likely related to L1 gene loss in cells containing integrated HPV type 16.

Human papillomavirus (HPV) infections have been implicated in anogenital neoplasia in both sexes. In this study, the authors postulated that HPV infections induce squamous epithelium to become hyperproliferative and aneuploid.To test this hypothesis, formalin fixed, paraffin embedded tissues were analyzed for the presence of HPV by in situ hybridization. S-phase fraction and DNA content were evaluated by flow cytometry. Proliferative indices also were analyzed using an antibody to proliferating cell nuclear antigen (PCNA).Human papillomavirus DNA was present in 48.1% of the carcinomas. All but one HPV-positive tumor contained HPV 16/18 DNA. The remaining tumor contained only HPV 6/11. No correlation was found between HPV status, patient age, or tumor differentiation. Thirty-three percent of tumors were aneuploid. Only two patients had aneuploid tumors that were HPV-negative; these patients received preoperative radiotherapy. The average S-phase fraction was significantly higher (P0.01) in HPV-positive versus HPV-negative lesions. The PCNA index for HPV positive tumors was also significantly higher than that observed in negative tumors (p0.003).The presence of HPV in tumor cells is significantly associated with an increased proliferative rate and aneuploid status of tumors compared with HPV-negative tumors. These findings are consistent with the fact that viral proteins binding to tumor suppressor gene proteins can deregulate the cell cycle and lead to genomic instability.

A total synthesis of the sulfated lipotetrasaccharide (NodRm-1) is described. First, the disaccharide glycosyl donor—O-(2-azido-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranosyl)-(1 →4)-3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl chloride 3a or the corresponding trichloroacetimidate 3b— and the disaccharide glycosyl acceptor — benzyl O-(3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl)-(1 →4)-3-O-benzyl-2-deoxy-2-phthalimido-6-O-pivaloyl-β-D-glucopyranoside 4 have been synthesized from monosaccharide moieties through a series of well established reactions. Then the crucial coupling between compound 4 and chloride 3a or imidate 3b gave the corresponding β-linked tetrasaccharide 2. Transformation of the protecting group and subsequent 6-O-sulfation converted tetrasaccharide 2 into the sulfated, N-acetylated compound 25. Finally, hydrogenolysis of compound 25, followed by selective N-acylation with 3-acylthiazolidine-2-thione 29, afforded NodRm-1 as its sodium salt.

Etude cinetique de l'hydrolyse de palmitate de p-nitrophenyle co-substitues (Br, SCH 3 , OH et SH) en presence et en l'absence de thiols ou d'amylose

Etude cinetique de l'hydrolyse de vingt et un esters phenyliques p-substitues d'acides alcanoiques avec diverses longueurs de chaines dans des melanges DMSO-eau

Etude cinetique de l'hydrolyse de vingt et un esters phenyliques p-substitues d'acides alcanoiques avec diverses longueurs de chaines dans des melanges DMSO-eau

Etude cinetique de l'hydrolyse de palmitate de p-nitrophenyle co-substitues (Br, SCH 3 , OH et SH) en presence et en l'absence de thiols ou d'amylose