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Biomedical subjects

Kai Zhang

Publications and source records attributed to Kai Zhang.

118 records · Page 7Linked to original sources
PubMed2002

[Physicians' knowledge and attitude to erectile dysfunction].

OBJECTIVES: The physicians knowledge and attitude to erectile dysfunction (ED) is very important to the diagnosis and management of this disease. We investigated the physicians and practitioners knowledge of ED, attitude to ED, and if they actively find the underlying ED patients. METHODS: Three hundreds and one physicians and practitioners in Beijing completed a questionnaire. The subjects included urologists, cardiologists, endocrinologists, surgeons, orthopaedicians and community practitioners. RESULTS: The definition of ED was well known by most subjects (83.4%). Many agreed that ED was a common condition in the aging men (85.0%), and it was an important health problem (78.7%) and it was the local signs of certain systemic diseases (89.7%). The most common risk factors of ED enumerated by the physicians were diabetes (45.5%), hypertension (12.6%) and coronary artery diseases (12.0%). 45.5% physicians met the patients who initiated questions about ED. 32.6% physicians would discuss ED with the patients if the patients initiate questions about ED. 95.0% non-urological physicians would refer the ED patients to urologists or andrologists. 43.5% of all the physicians never asked their patients about erectile function, this proportions in the subgroups of urologists, non-urological physicians and community practitioners were 7.2%, 55.3% and 60.5% respectively (P < 0.01). The most common reasons for the physicians not to initiate the inquiries about ED was "the patients would not have ED if they didnt complain about it" (42.2%), "there was no ED patients in my specialty" (20.9%), "diagnosis and treatment of ED was not my business" (17.3%), "have no time" (15.6%), "feel embarrassed" (13.6%). CONCLUSIONS: Most physicians regarded ED as an important health problem and a common condition in aging men, but they didnt take an active attitude to ED in their clinical practice.

Aging↗
PubMed2002

[The intervention effects of Angelica sinensis, Salvia miltiorrhiza and ligustrazine on peritoneal macrophages during peritoneal dialysis].

OBJECTIVE: To study the effect of Angelica sinensis, Salvia miltiorrhiza and Ligustrazine on function of peritoneal macrophages during peritoneal dialysis. METHODS: Peritoneal macrophages of mice were cultured in culture medium (control), peritoneal dialysate (PD), drugs contained PD containing Angelica, Salvia and Ligustrazine combined (PD-ASL) or separated (PD-A, PD-S, PD-L) with concentration of 2 micrograms/ml, 10 micrograms/ml and 100 micrograms/ml, separately for 24 hrs. The nitric oxide (NO) content, methyl thiazolyl tetrazolium (MTT) reducing capacity (MTT-RC) and phagocytosis capacity of macrophages were determined and compared. RESULTS: NO content and MTT-RC of macrophages cultured in PD group were significantly lower than those of the control (P < 0.01), as compared with those in drug contained PD groups, the NO content in the PD-L group and the MTT-RC in the PD-ASL group were higher significantly (P < 0.01). The phagocytosis capacity and NO content in the PD-ASL group were raised along with the increased concentration of drug in PD. CONCLUSION: Administering Chinese herbal medicine during peritoneal dialysis has important significance in improving the defense function of peritoneal macrophages, reducing the incidence of peritonitis and enhancing the therapeutic effect of peritoneal dialysis.

Angelica sinensis↗
PubMed2002

[Landscape ecological studies on autumnal Chinese cabbage fields in Shenyang city suburb. I. Features of autumnal Chinese cabbage field patches].

Some typical patches of autumnal Chinese cabbage fields in the agricultural landscapes of Shenyang city suburb were investigated, and their basic features, such as areas, shapes, neighborings and connections, were recorded. Their mosaic features were also analyzed and discussed. In the region of less 5 km distance from city, many Chinese cabbage patches neighbored each other and connected to highways, while in the region of 5-10 km distance from city, they neighbored with corn patches and connected to countryside roads. In the region over 10 km distance from city, many Chinese cabbage patches are surrounded by corn patches and connected to countryside roads.

Agriculture↗
PubMed2002

[Landscape ecological studies on autumnal Chinese cabbage fields in Shenyang city suburb. II. Relationship between Chinese cabbage field patches and their neighboring landscape elements].

The relationship between autumnal Chinese cabbage patches and their neighboring other lanascape elements were studied in Shenyang suburb. The groups and quantities of arthropods moving through a boundary between a Chinese cabbage patch and its neighboring corn patch in certain period, were investigated and the 7 oders of arthropods moving through the boundary with an average flow of 10.3 individuals.m-1.d-1 were observed. The changes of falling dust rates on a Chinese cabbage patch near a countryside road are analyzed. Some principles of agroecosystems in an agricultural landscape were discussed on the basis of these observation results.

Agriculture↗
PubMedDate not supplied

Cloning and molecular characterization of cGMP-gated ion channels from rod and cone photoreceptors of striped bass ( M. saxatilis ) retina.

Vertebrate photoreceptors respond to light with changes in membrane conductance that reflect the activity of cyclic-nucleotide gated channels (CNG channels). The functional features of these channels differ in rods and cones; to understand the basis of these differences we cloned CNG channels from the retina of striped bass, a fish from which photoreceptors can be isolated and studied electrophysiologically. Through a combination of experimental approaches, we recovered and sequenced three full-length cDNA clones. We made unambiguous assignments of the cellular origin of the clones through single photoreceptor RT-PCR. Synthetic peptides derived from the sequence were used to generate monospecific antibodies which labeled intact, unfixed photoreceptors and confirmed the cellular assignment of the various clones. In rods, we identified the channel alpha subunit gene product as 2040 bp in length, transcribed into two mRNA 1.8 kb and 2.9 kb in length and translated into a single 96-kDa protein. In cones we identified both alpha (CNGA3) and beta (CNGB3) channel subunits. For alpha, the gene product is 1956 bp long, the mRNA 3.4 kb, and the protein 74 kDa. For beta, the gene product is 2265 bp long and the mRNA 3.3 kb. Based on deduced amino acid sequence, we developed a phylogenetic map of the evolution of vertebrate rod and cone CNG channels. Sequence comparison revealed channels in striped bass, unlike those in mammals, are likely not N-linked-glycosylated as they are transported within the photoreceptor. Also bass cone channels lack certain residues that, in mammals, can be phosphorylated and, thus, affect the cGMP sensitivity of gating. On the other hand, functionally critical residues, such as positively charged amino acids within the fourth transmembrane helix (S4) and the Ca(2+)-binding glutamate in the pore loop are absolutely the same in mammalian and nonmammalian species.

Amino Acid Sequence↗
PubMedDate not supplied

Characterization of nanostructure of stimuli-responsive polymeric composite membranes.

To elucidate the mechanism of stimuli-responsive permeability and to optimize the design, the nanostructure of polymeric composite membranes, developed in our laboratory, was characterized. The membranes were prepared to contain various amounts of stimuli-responsive nanoparticles of poly(N-isopropylacrylamide-co-methacrylic acid), with or without polyelectrolyte coating. Scanning electron microscopy and X-ray photoelectron spectroscopy were used respectively to examine the morphology and surface chemical composition, whereas atomic force microscopy and laser scanning confocal microscopy were employed to characterize the in situ surface and internal structure of the membranes in aqueous media of various pHs. The porous structure was evidenced in the presence of the nanoparticles. The surface content of the nanoparticles increased with increasing particle concentration while the polyelectrolyte coating was nearly undetectable. AFM images revealed that the particles in the membranes shrank with a concomitant increase in pore size as the buffer pH decreased. LSCM results indicated that particles were distributed through the membrane as interconnected clusters.

Acrylamides↗
PubMedDate not supplied

In situ formation of blends by photopolymerization of poly(ethylene glycol) dimethacrylate and polylactide.

Blends of cross-linked poly(ethylene glycol) dimethacrylate (PEGDMA) and poly(d,l-lactide) (PLA) were prepared by mixing photoactive PEGDMA (molecular mass: 875 g/mol) and PLA, and subsequently photopolymerizing the mixture with visible light. The effects of PLA molecular mass and mass fraction on the rheological properties of the PEGDMA/PLA mixtures, and on the degree of methacrylate vinyl conversion (DC), as well as blend miscibility, microstructure, mechanical properties, in vitro swelling behavior, and cell responses were studied. PLA-2K (molecular mass: 2096 g/mol) and PLA-63K (molecular mass: 63 000 g/mol) formed miscible and partially miscible blends with cross-linked PEGDMA, respectively. The addition of the PLA-2K did not affect the immediate or post-cure (>24 h) DC of the PEGDMA upon photopolymerization. However, the addition of PLA-63K decreased the immediate DC of the PEGDMA, which can be increased through extending the curing time or post-curing period. Compared to the cross-linked neat PEGDMA and PLA-2K/PEGDMA blends, PLA-63K/PEGDMA blends were significantly stronger, stiffer, and tougher. Both types of blends and the cross-linked PEGDMA swelled when soaked in a phosphate buffered saline (PBS) solution. The attachment and spreading of MCT3-E1 cells increased with increasing PLA-63K content in the blends. The facile and rapid formation of PEGDMA/PLA blends by photopolymerization represents a simple and efficient approach to a class of biomaterials with a broad spectrum of properties.

Acrylates↗
PubMedDate not supplied

Increased protein identification capabilities through novel tandem MS calibration strategies.

High mass measurement accuracy is critical for confident protein identification and characterization in proteomics research. Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a unique technique which can provide unparalleled mass accuracy and resolving power. However, the mass measurement accuracy of FTICR-MS can be affected by space charge effects. Here, we present a novel internal calibrant-free calibration method that corrects for space charge-induced frequency shifts in FTICR fragment spectra called Calibration Optimization on Fragment Ions (COFI). This new strategy utilizes the information from fixed mass differences between two neighboring peptide fragment ions (such as y(1) and y(2)) to correct the frequency shift after data collection. COFI has been successfully applied to LC-FTICR fragmentation data. Mascot MS/MS ion search data demonstrate that most of the fragments from BSA tryptic digested peptides can be identified using a much lower mass tolerance window after applying COFI to LC-FTICR-MS/MS of BSA tryptic digest. Furthermore, COFI has been used for multiplexed LC-CID-FTICR-MS which is an attractive technique because of its increased duty cycle and dynamic range. After the application of COFI to a multiplexed LC-CID-FTICR-MS of BSA tryptic digest, we achieved an average measured mass accuracy of 2.49 ppm for all the identified BSA fragments.

Algorithms↗
PubMedDate not supplied

Self-reported antibiotic compliance: emergency department to general practitioner follow up.

BACKGROUND: General practitioner (GP) follow up is important in the management of patients who are discharged from an ED. OBJECTIVES: To determine the antibiotic compliance and GP follow-up compliance rates in a population of patients seen and discharged from the ED with an antibiotic prescription. To test the hypothesis that the ability to nominate a GP is associated with improved antibiotic and GP follow-up compliance. DESIGN: A prospective cohort study enrolling consecutive adults who were discharged from the ED with antibiotic prescriptions over a 3 month period. Patients were divided into those who nominated a GP at the time of ED presentation and those who did not. Two weeks after enrollment, patients were contacted and asked standardized questions regarding compliance. RESULTS: In total, 123 patients were enrolled into the study. Of patients 76% were able to nominate a GP upon ED presentation. Analysis revealed that those patients who were able to nominate a GP had better compliance to follow up instructions (85 vs 44%, P < 0.01) and improved antibiotic compliance (99 vs 88%, P = 0.01). CONCLUSION: The majority of patients who were seen and discharged from the ED with an antibiotic prescription were able to nominate a GP and this was associated with improved follow-up compliance and antibiotic compliance. Improving follow-up compliance and thus the quality of patient care would involve identifying those patients who present to the ED who are unable to nominate a GP.

Adolescent↗