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Biomedical subjects

W J Wang

Publications and source records attributed to W J Wang.

At least 19 recordsLinked to original sources
PubMed1996

Improvement of projection-type associative memories by using a two-phase recalling procedure.

In this letter, we propose a Two-Phase Recalling Procedure (TPRP) to improve the recall capability of the projection-type associative memory. It is known that the conventional projection dynamic sometimes produces spurious states that do not belong to the space spanned by the prototype vectors (memory space). The proposed TPRP provides a trapped spurious state another chance to project onto the memory space such that the recall capability of the projection-type associative memories can be greatly improved. Finally a simulation result demonstrates the effectiveness of the TPRP.

Computer Simulation↗
PubMed1996

Equilibrium and attractivity analysis for a class of hetero-associative neural memories.

Based on the natural structure of Kosko's Bidirectional Associative Memories (BAM), a high-performance, high-capacity associative neural model is proposed which is capable of simultaneous hetero-associative recall. The proposed model, Modified Bidirectional Decoding Strategy (MBDS), improves the recall rate by adding some association fascicles to Kosko's BAM. The association fascicles are sparse coding neuron structures that provide activating strengths between two neuron fields (say, field X and field Y). The sufficient conditions for a state to become an equilibrium state of the MBDS network is derived. Based on these results, we discuss the basins of attraction of the training pairs in one iteration. The upper bound of the number of error bits which can be tolerated by MBDS is also derived. Because the attractivity of a stored training pair can be increased markedly with the aid of its corresponding association fascicles, we recommend a high capacity realization of MBDS, Bidirectional Holographic Memory (BHM), so that each training pair is stored uniquely and directly in the connection weights rather than encoded in a correlation matrix. Finally, computer simulations demonstrate the attractiveness of three different realizations of MBDS to verify our results.

Association↗
PubMed1996

Characteristics of ground reaction forces in normal and chimpanzee-like bipedal walking by humans.

Bipedal walking by common chimpanzees is known to differ both kinematically and kinetically from human bipedalism, in particular by the adoption of flexed-knee gaits and characteristically single-peaked vertical ground reaction force curves. This study provides a test of the proposition that the two former mechanical characteristics are functionally related. Further, it examines the pattern of forces occurring during normal human bipedal walking at slow, normal and fast velocities; and during walking imitating bipedal walking of the common chimpanzee, by both male and female human adults and children. The data suggest naturally reared chimpanzees walk with greater lateral forces than do adult humans walking erect. Women show greater variance in force parameters than do men; and children more than do adults, but men walk with greater vertical accelerations of the centre of mass, and sharper peaks of sagittal acceleration and deceleration than women. Data from both forceplate and pressure-pad records suggest that young children (and a chimpanzee for which forceplate data was available) accelerate using the heel, rather than the anterior part of the foot. A principal component analysis of Fourier coefficients for the force curves shows that forces produced by adults imitating chimpanzee gaits are intermediate between those produced in normal human gait and those produced by 'real' chimpanzees, confirming a functional connection between knee and hip kinematics during bipedal walking and the shape of the vertical ground reaction force curve. Human flexed-knee, flexed-hip walking is found to produce in-phase fluctuations in potential and kinetic energies, preventing the energy exchange which obtains in erect walking. Finally, computer simulations of bipedal walking indicate that kinematics are more influential determinants of ground reaction forces than are body parameters.

Adult↗
PubMed1996

[Study on effect of strengthening body resistance method on asthmatic attack].

In order to study the effect of strengthening body resistance method on asthmatic attack, asthma patients of Cold type and Heat type were treated with symptomatic treatment (as control groups), and treatment both on the principal and secondary aspect (as test group) respectively. The results showed that the markedly effective rates of the test groups of both type were higher than that of the two control groups. In test groups after treatment, the 1 second forced expiratory volume (FEV1) and the maximal expiratory flow increased markedly, the human leucocyte antigen carrying (HLA-DR+) T cell ratio, the basophilic cell releasing capacity (HBR) and the T cell hyperplasia response to specific allergen were all reduced. While in the control groups, these criteria had no significant changes after treatment. These results suggested that the strengthening body resistance method displayed an obvious regulating action in relieving attack of asthma.

Adult↗
PubMed1996

[A genetic epidemiologic study on HBsAg chronic carriers].

375 Individuals from 23 HBsAg positive families were investigated in the study. The results showed that HBsAg carrier rate among blood relatives was significantly higher than non-blood relatives (P < 0.01); HBsAg carrier rate decreased with the order of the first, second and third degree relatives (P < 0.01); and the rate in the individuals living together with the probands was higher than those living apart (P < 0.01). However, the other two markers of HBV infectivity, anti-HBs and anti-HBc, did not show any differences mentioned above. The results analysed by means of dichotomy and Logistic regression model, showed that blood relationship played an important role in HBsAg carrier state. In addition, the history of sharing living facilities was related to HBsAg carrier state. The average heritability in the first, second and third degree relatives was 79.68%. The analysis of genetic model showed that HBsAg carrier state was corresponded to the characteristic of multifactorial genetic disease, excluding the possibility of genetic disease due to single gene.

Carrier State↗
PubMed1995

A correlation significance learning scheme for auto-associative memories.

A new concept called correlation significance for expanding the attraction regions around all the stored vectors (attractors) of an asynchronous auto-associative memory is introduced. Since the well known outer product rule adopts equally-weighted correlation matrix for the neuron connections, the attraction region around each attractor is not maximized. In order to maximize these attraction regions, we devise a rule that all the correlations between two different components of two different stored patterns should be unequally weighted. By this formalism, the connection matrix T of the asynchronous neural network is designed by using the gradient descent approach. Additionally, an exponential type error function is constructed such that the number of successfully stored vectors can be directly examined during the entire learning process. Finally, computer simulations demonstrate the efficiency and capability of this scheme.

Computer Simulation↗
PubMed1995

Feasibility of milk fluoridation and trends in dental caries of children in China.

The aim of the study is to investigate the feasibility of milk fluoridation as a vehicle for caries prevention, based on the current epidemiological status and its trends of dental caries in preschool children in the area of the Haidian District of Beijing, where the indications exist: Fluoride level in drinking water is low (0.2-0.3 ppm), and water fluoridation and other systemic uses of fluorides are unlikely. From 75.9 to 79.7% of 3-6-year-old children were identified as having high caries experience (dmft 4.29-4.35). It was found that 60% of the preschool children who attended kindergarten were 3-6 years old, and 40% of the 1-2-year-olds were living with their families. There is a local dairy to produce milk for the population living in this district. The amount of fresh milk produced daily is about 50,000-60,000 kg. A special kind of milk with vitamins A and D is also available for the preschool children. Data available from the Community MCH Centre indicated that the percentage of breast-feeding is 12% only. The first choice by parents for artificial feeding to the babies is fresh or powdered milk. Therefore, the breast-feeding project started in 1992. It is recommended that mothers' milk should be provided to the babies for at least four months after birth, when a specially prescribed milk for the babies, produced by the dairy, will be provided on a daily basis. The cost of milk is cheaper than others. In this connection, a five-year project on milk fluoridation as a pilot study at the community level for caries prevention of preschool children is now planned. The project is supported by BDMF, WHO, and Chinese MOPH.

Animals↗
PubMed1994

Systemic amyloidosis. A report of 19 cases.

Systemic amyloidosis is a rare disorder and usually occurs in aged persons with a poor prognosis. Certain mucocutaneous symptoms and signs may act as important clues for diagnosis. Skin or tongue biopsy may also provide important information to establish a firm diagnosis. During the past 14-year period, we found 19 cases of systemic amyloidoses: 8 (42%) with primary systemic amyloidosis, 8 (42%) associated with multiple myeloma and 3 (16%) were secondary amyloidosis. Ages of the patients ranged from 52 to 71 years with a mean age of 62 years at diagnosis. Median survival was only 8 months. Mucocutaneous manifestations were found in both primary type and myeloma-associated amyloidosis. In addition to the existence of amyloid in tongue and rectum biopsies in 17 cases and abdominal fat aspiration in 1 case, biopsies from clinically normal-looking skin also showed positive results in 18 out of 19 cases.

Aged↗
PubMed1994

[Clinical study on comparison of tonifying kidney replenishing vitality and removing blood stasis and resolving mass in the treatment of prostatic hyperplasia].

70 patients with prostatic hyperplasia were observed. Among them 34 cases were treated with the regime of tonifying Kidney-replenishing Vitality (TKRV) and the other 36 cases were treated with removing blood stasis and resolving mass (Xiao Jin Dan). The dysuria of the patients in both groups was improved after treatment. The results of the transrectal ultrasonotomography showed as follows: (1) The effect on the volume of residual urine: the average values of the TKRV group were 43.29 +/- 14.03 ml before treatment and 17.24 +/- 5.13 ml after treatment (P < 0.05), that of Xiao Jin Dan were 21.17 +/- 5.57 ml and 7.37 +/- 2.87 ml respectively (P < 0.01). (2) The effect on the size of the prostate gland: only 10 cases in the TKRV group were measured both before and after treatment, the average size of the prostate gland were 46.30 +/- 8.23 ml and 43.60 +/- 4.52 ml respectively (P < 0.05), and 4 cases were decreased in the size after treatment. 35 cases in Xiao Jin Dan group were measured before and after treatment and their size of prostate gland were 47.83 +/- 2.50 ml and 43.45 +/- 2.24 ml (P < 0.01) respectively. 27 out of the 35 cases were decreased in their size of prostate gland. The results showed that the therapeutic effect of Xiao Jin Dan was slightly better than that of the TKRV, which suggested that the prostatic hyperplasia was closely related to the syndrome of Kidney-Deficiency as well as to the syndrome of Blood Stasis. So it is important that we combined the reinforcement and elimination in the treatment of prostatic hyperplasia.

Aged↗
PubMed1994

[Research on effect of kidney tonifying herbs on senile neuroendocrine-immunity].

Kidney Tonifying Herbs (KTH) exerted their effects on reserve function of the adrenal cortex and lymphocytic receptor of glucocorticoid. The therapeutic mechanism of KTH was explored with respect of function in endocrine axes and neurotransmitter in hypothalamus. The conclusion was that the senile hypothalamic function played an important role in the declining of neuroendocrine immunity function. KTH might regulate the function of hypothalamus, delaying the aging of neuroendocrine-immunity disturbance. The way of KTH effect might be the function of comprehensive coordination of the multicomponents, multilayers, multilinks and multipathways.

Adrenal Cortex↗
PubMed1994

[Management of dislocated or subluxated posterior chamber intraocular lens].

The experiences of the management of 20 cases (20 eyes) of intraocular lens (IOL) dislocation or subluxation were summarized in this report. All the patients underwent primary extracapsular cataract extraction with posterior chamber IOL implantation. The dislocation or subluxation occurred in 2 eyes intraoperatively and 18 eyes in 1 day to 3 years, post-operatively. The IOLs were captured at pupils in 12 eyes, dislocated into the vitreous in 4 eyes, represented as in westeast syndrome in 2 eyes and sunset and sunrise syndrome in 1 eye and 1 eye, respectively. Of the 20 eyes, 1 eye with mild sunset syndrome was treated with a miotic, 2 eyes with IOL pupillary capture were treated successfully by conservative therapy and the rest, by surgeries. In cases treated by operations, the IOLs were removed from original incisions in 3 eyes, by vitrectomies in 5 eyes and surgical reposition of IOLs were undertaken in 9 eyes with IOL pupillary capture of which 7 eyes were successful and in 2 eyes recurrence took place shortly after reposition. The causes and management of IOL dislocation or subluxation were discussed.

Adolescent↗
PubMed1994

[Treatment of ocular injury with lensectomy and closed vitrectomy].

The authors reviewed 104 consecutive cases of ocular injury treated with lensectomy and closed vitrectomy including anterior segment resection in 80 cases and posterior segment, in 24 cases. The curative rate was 80.8%. Post-operatively, 44 eyes (47.8%) gained visual acuities of 0.025-0.6 and 68 eyes (65.4%) obtained visual improvement. 29 eyes were followed up 1-38 months, averaging 22.5 months, to find long-term therapeutic effects in 23 eyes (79.3%). The authors believe that lensectomy with closed vitrectomy is a useful modality in treatment of ocular injury.

Adolescent↗
PubMed1994

[The antiinflammatory activity of shikonin and its inhibitory effect on leukotriene B4 biosynthesis].

Shikonin is one of the active components isolated from the dry root of Arnebia euchroma (Royle) Johnst (AERJ). It has been shown to have anti inflammatory activity on formaldehyde induced paw swelling in rats. Preparations of AERJ has been used clinically in curing phlebitis and vascular purpura. In the present study, sc administered shikonin was shown to have significant inhibitory effects on ear edema induced by croton oil in mice and paw swelling induced by yeast in rats. In order to investigate the influence of shikonin on biosynthesis of LTB4 and 5-HETE, an in vitro leukocyte incubation system was adopted. The results showed that shikonin has fairly strong inhibitory effects on LTB4 and 5-HETE biosynthesis. Its effects and concentrations fit a positive relationship within the range of 10(-7)-10(-4) mol.L-1. The equations of inhibition (Y) versus concentration (X, LogC) obtained by linear regression were Y = 166 + 18.7X (r = 0.9319) for LTB4 and Y = 173 + 18.7X (r = 0.9856) for 5-HETE. The IC50 were 6.2 x 10(-7) and 2.6 x 10(-7) mol.L-1, respectively. The results also indicate that natural shikonin derivatives have similar inhibitory effects on LTB4 biosynthesis. These results suggest that inhibition of LTB4 and 5-HETE may play a major role in the mechanism of anti inflammatory effects of shikonin.

Animals↗