Space-efficient optical computing with an integrated chip diffractive neural network.

Large-scale, highly integrated and low-power-consuming hardware is becoming progressively more important for realizing optical neural networks (ONNs) capable of advanced optical computing. Traditional experimental implementations need N2 units such as Mach-Zehnder interferometers (MZIs) for an input dimension N to realize typical computing operations (convolutions and matrix multiplication), resulting in limited scalability and consuming excessive power. Here, we propose the integrated diffractive optical network for implementing parallel Fourier transforms, convolution operations and application-specific optical computing using two ultracompact diffractive cells (Fourier transform operation) and only N MZIs. The footprint and energy consumption scales linearly with the input data dimension, instead of the quadratic scaling in the traditional ONN framework. A ~10-fold reduction in both footprint and energy consumption, as well as equal high accuracy with previous MZI-based ONNs was experimentally achieved for computations performed on the MNIST and Fashion-MNIST datasets. The integrated diffractive optical network (IDNN) chip demonstrates a promising avenue towards scalable and low-power-consumption optical computational chips for optical-artificial-intelligence.

An optical neural chip for implementing complex-valued neural network.

Complex-valued neural networks have many advantages over their real-valued counterparts. Conventional digital electronic computing platforms are incapable of executing truly complex-valued representations and operations. In contrast, optical computing platforms that encode information in both phase and magnitude can execute complex arithmetic by optical interference, offering significantly enhanced computational speed and energy efficiency. However, to date, most demonstrations of optical neural networks still only utilize conventional real-valued frameworks that are designed for digital computers, forfeiting many of the advantages of optical computing such as efficient complex-valued operations. In this article, we highlight an optical neural chip (ONC) that implements truly complex-valued neural networks. We benchmark the performance of our complex-valued ONC in four settings: simple Boolean tasks, species classification of an Iris dataset, classifying nonlinear datasets (Circle and Spiral), and handwriting recognition. Strong learning capabilities (i.e., high accuracy, fast convergence and the capability to construct nonlinear decision boundaries) are achieved by our complex-valued ONC compared to its real-valued counterpart.

Silicon photonic integrated circuits with electrically programmable non-volatile memory functions.

Conventional silicon photonic integrated circuits do not normally possess memory functions, which require on-chip power in order to maintain circuit states in tuned or field-configured switching routes. In this context, we present an electrically programmable add/drop microring resonator with a wavelength shift of 426 pm between the ON/OFF states. Electrical pulses are used to control the choice of the state. Our experimental results show a wavelength shift of 2.8 pm/ms and a light intensity variation of ~0.12 dB/ms for a fixed wavelength in the OFF state. Theoretically, our device can accommodate up to 65 states of multi-level memory functions. Such memory functions can be integrated into wavelength division mutiplexing (WDM) filters and applied to optical routers and computing architectures fulfilling large data downloading demands.

Inconsistency and comprehensiveness of risk assessments for heavy metals in urban surface sediments.

Numerous indices have been developed to assess environmental risk of heavy metals in surface sediments, including the total content based geoaccumulation index (I(geo)), exchangeable fraction based risk assessment code (RAC), and biological toxicity test based sediment quality guidelines (SQGs). In this study, the three indices were applied to freshwater surface sediments from 10 sections along an urbanization gradient of the Grand Canal, China to assess the environmental risks of heavy metals (Cu, Pb, Zn, Cd, and Cr) and to understand discrepancies of risk assessment indices and urbanization effects regarding heavy metal contamination. Results showed that Cd, Zn, and Pb were the most enriched metals in urban sections assessed by I(geo) and over 95% of the samples exceeded the Zn and Pb thresholds of the effect range low (ERL) of SQGs. According to RAC, Cu, Zn, Cd, and Cr had high risks of adversely affecting the water quality of the Grand Canal due to their remarkable portions of exchangeable fraction in surface sediment. However, Pb showed a relative low risk, and was largely bounded to Fe/Mn oxides in the urban surface sediments. Obviously, the three assessment indices were not consistent with each other in terms of predicting environmental risks attributed to heavy metals in the freshwater surface sediments of this study. It is recommended that risk assessment by SQGs should be revised according to availability and site specificity. However, the combination of the three indices gave us a comprehensive understanding of heavy metal risks in the urban surface sediments of the Grand Canal.

Field assessment of recombinant Schistosoma japonicum 26 kDa glutathione S-transferase in Chinese water buffaloes.

We have shown previously that anti-fecundity immunity can be induced experimentally against recombinant 26 kDa glutathione S-transferase (reSjc26GST) in Chinese water buffaloes (Bos buffelus), important reservoir hosts for Schistosoma japonicum in China. In the field study described here, we immunized buffaloes with reSjc26GST to induce protective immunity against S. japonicum and to evaluate its effectiveness in controlling schistosomiasis japonica. We selected two villages as test and control groups in inside-embankment areas endemic for schistosomiasis japonica. The buffaloes in the test village were vaccinated with reSjc26GST, whereas those in the control village were not. The indicators of the effect of the vaccine included the generation of specific IgG antibodies in the vaccinated buffaloes, changes in the prevalence and infection intensity in buffaloes and village children, changes in the density of infected snails, and changes in the infectivity of water bodies (assessed by sentinel mice) in transmission areas adjacent to both villages. Twenty months after vaccination, the infection rate of buffaloes in the test village was decreased by 60.4% (from an initial prevalence of 13.5% to 5.4%), and 67.9% when compared with that in the control village (initial prevalence of 16.7%). However, the infection rate in village children remained unchanged. The density of infected snails decreased by 71.4%, from 0.0049/0.11 m2 to 0.0014/0.11m2 in the high transmission area outside the embankment in the test village. There was no change in the infectivity of the water body transmission areas between the test and control villages. The levels of specific antibodies to reSjc26GST showed a continuous increase after vaccination. These results indicate that protective immunity was induced and maintained in buffaloes after vaccination with reSjc26GST. The vaccine could thus play a significant role in reducing S. japonicum transmission caused by water buffaloes in the Lake region of China.

Antibody isotype responses to Schistosoma japonicum antigens in subjects from a schistosomiasis area with repeated praziquantel chemotherapy compared with a new endemic zone in Hunan Province, P.R. China.

To demonstrate the dynamics of specific antibody isotypes against schistosome adult worm (AWA) and soluble egg (SEA) antigens, we evaluated (in 1999-2000) 112 subjects infected with Schistosoma japonicum from 2 regions of Hunan Province, China. Fifty-eight subjects were from Area A, a well-known endemic area with repeated chemotherapy. Area B (n = 54) is a new endemic focus in another part of the same province. Serum samples were collected prior to praziquantel (PZQ) chemotherapy, and at 2 and 12 months post-treatment. IgM, IgA, IgG, IgG2, IgG4 and IgE antibodies to AWA and SEA were measured by quantitative enzyme-linked immunosorbent assay (ELISA). Pre-treatment antibody isotype levels from Area A, except IgA against AWA and SEA, were significantly higher than those from Area B. In response to chemotherapy, most antibody isotype levels fell or remained stable. However, in Area A there was a significant increase in the IgA, IgE and IgG4 responses to AWA 2 months after PZQ--which fell to approach pre-treatment levels by 12 months. A similar response was seen in Area B with IgE and IgG4 to AWA. Levels of all AWA-specific IgE and IgG4 were significantly higher in subjects from Area A compared with Area B at all time-points. AWA-IgE levels demonstrated significant linear correlations with age and number of previous PZQ treatments in Area A only. All SEA-specific isotypes in both areas fell significantly in response to treatment--except IgE, which remained stable in both area. All SEA-specific isotype levels (except IgA) were significantly higher from Area A at baseline. This significant difference was maintained through 12-months follow-up for IgE, IgG2 and IgG4 only. This study suggests that multiple episodes of schistosome infection may be required to generate antibody isotype levels that have been associated with resistance to re-infection in other studies. Further, a surrogate marker of successful chemotherapy (AWA-IgG4) performed less effectively in patients with previous treatment courses.

[A study on the recombinant 26 kDa glutathione-S-transferase as a vaccine candidate: dynamics of antibodies in immunized buffaloes and protection against Schistosoma japonicum infections].

OBJECTIVE: To observe the dynamics of antibodies and protection against Schistosoma japonicum infections in buffaloes after immunized with recombinant 26 kDa glutathione-S-transferase (reSjc26GST). METHODS: Buffaloes in 2 villages endemic for schistosomiasis japonica were selected as test and control groups, respectively. In test group initially 96 buffaloes were vaccinated with reSjc26GST, and 90 buffaloes in the control group did not experience vaccination. The indicators included levels of antibodies to reSjc26GST in buffaloes before and after infection with S. japonicum and changes in infection rate. RESULTS: Specific antibodies, which showed a trend of trapezoid increase, were induced in buffaloes after immunized with reSjc26GST. Twenty months after immunization, the infection rate of the test group was decreased by 62.2% when compared with that before vaccination, and by 67.7% when compared with that of the control in the corresponding period. CONCLUSION: Specific antibodies and a certain extent of protection were induced in buffaloes after immunized with reSjc26GST, which played an significant role in ameliorating morbidity.

[Preliminary report on immunoscreening of Schistosoma japonicum adult worm cDNA library by sera from infected Microtus fortis].

Microtus fortis (Mf) is resistant to Schistosoma japonicum (Sj) infection. To explore if Mf responses to special Sj antigens after infection, Sj adult worm cDNA library was screened with sera from infected Mf. Twelve positive clones were obtained after rescreening. After automatically excised with the helper phage, positive clones were further identified by PCR. The size of Sj cDNA fragments in positive clones ranged from 300 bp to 1.8 kb. Six of these fragments were 300 bp, one was 1 kb, and five were 1.8 kb in size. The results indicate that the infected Mf serum could recognize Sj specific antigens. It is valuable to further study the immune protection of these cloned molecules.

[Therapeutic effect of liposome on II degree burn wound].

OBJECTIVE: To study the therapeutic effect of Suyuping in which liposome is the main constituent on II degree burn wound. METHODS: From October 1998 to October 1999, 42 cases with II degree burn wound were adopted in this study. Among them, there were 30 males and 12 females, the average wound area was (23.4 +/- 9.7)%. The wounds on the left side of body were managed with sulfadiazine argentum(SD-Ag) while that on the right side with Suyuping. Healing and other situation about the burn wounds were observed and recorded at times. RESULTS: Forty-two patients completely healed when discharged from hospital. The average wound area managed with Suyuping was (11.2 +/- 7.3)% and the area with SD-Ag was (9.4 +/- 5.8)%. The mean healing time of Suyuping group was(18.4 +/- 4.7) days while that of SD-Ag was (23.5 +/- 7.9) days, there was significant difference(P < 0.05). Suyuping group presented few wound pain, allergy, bleeding and the side effect was less. CONCLUSION: Suyuping can accelerate wound healing and attenuate wound pain, allergy and bleeding, it is a potential and specific topical agent for treating II degree burn wound.

Natural antibodies in Microtus fortis react with antigens derived from four stages in the life-cycle of Schistosoma japonicum.

The levels of antibodies which react with the cercarial antigens (CA), schistosomulum stage antigens (SSA), adult-worm antigens (AWA) and soluble egg antigens (SEA) of Schistosoma japonicum were investigated in Microtus fortis and albino mice, using an indirect ELISA. The M. fortis studied fell into three groups: animals caught in the wild; laboratory-bred animals left unchallenged; and laboratory-bred animals that had been challenged with S. japonicum (30 cercariae/animal) 15 days previously. There were also three groups of albino mice: those without infection; those studied 15 days after challenge infection; and those investigated 42 days after infection. The antibodies detected at the highest levels in the laboratory-bred, uninfected voles and in the wild-caught animals were those reacting with SSA, followed, in descending order, by those reacting with AWA, CA and SEA. The levels of natural antibodies to SSA and AWA in these voles were significantly higher than the corresponding levels observed in the uninfected mice and even in the mice infected 15 days previously. The levels of antibodies reacting with CA, SSA, SEA and AWA in the experimentally infected M. fortis were 1.9-, 2.2-, 1.5- and 2.1-fold higher, respectively, than those in the laboratory-bred but uninfected voles. The observations indicate that even uninfected M. fortis produce antibodies which react with S. japonicum, and this presumably results in the natural resistance to infection which has been reported in these rodents.

[Effect of L-arginine supplementation on partial-thickness burned patients].

OBJECTIVE: L-arginine is a semiessential dibasic amino acid for humans and animals. This paper aims to investigate the therapeutic effect of L-arginine supplementation on partial-thickness burned patients. METHODS: A randomized controlled clinical trial was designed to evaluate the cellular immune function (T cell count, ratio of CD4/CD8, natural killer cell activity and IL-2 level) and protein metabolism (transferrin, prealbium and nitrogen balance) of patients in the experimental group which daily given 15 g arginine and the control group which daily given 25 g glycine. RESULTS: The natural killer cell activity and IL-2 production in the experimental group were higher than that of the control group. The suppression of transferrin and prealbium was alleviated and the nitrogen balance was improved in the experimental group. CONCLUSION: It suggests that exogenous arginine supplementation is beneficial for recovery of cellular immunity function and protein anabolism in partial-thickness burned patients.

Diagnosis of schistosomiasis japonica in Chinese schoolchildren by administration of a questionnaire.

This paper describes a rapid, simple, cost-effective questionnaire for screening school-aged children at risk for Asian schistosomiasis in China. Five hundred and thirty-two children, aged 8-14 years, were selected from 3 schools in an area moderately endemic for Schistosoma japonicum in Hunan province. The questionnaire, comprising 15 multiple-choice questions, was administered by teachers in order to collect both ethnographic and epidemiological data relevant to current S. japonicum infections. This was followed by Kato-Katz thick smear stool examinations, miracidium hatching tests, and soluble egg antigen-enzyme linked immunosorbent assays in order to validate the efficacy of the questionnaire approach. The results from a combination of all 3 procedures indicated that the overall schistosomiasis prevalence in the 3 schools was 29.9% (138/472). Six risk factors (episodes of diarrhoea, frequency of water contact, school grade attained, weakness, past history of S. japonicum infection(s), and whether a subject had been previously treated for schistosomiasis) in the questionnaire were determined by logistic regression to be highly statistically significant predictors of individual current infection. The sensitivity (93.7%), specificity (91.9%) and low cost (c. US$ 0.6/true positive case) associated with the 6 variables model make the questionnaire approach a very useful diagnostic tool for screening marshland and lake communities at high risk for schistosomiasis in China before selective treatment with praziquantel or diagnostic follow-up. An even simpler 3 variables 'yes/no' model was derived from the questionnaire and found to be nearly as good at predicting individual infection (sensitivity 86.2% and specificity exceeding 97.6%) and extremely simple to use. If validated in other ecological settings in China the questionnaire, modified or as presented here, could be adopted by the national schistosomiasis control programme.

Serological diagnosis of Schistosoma japonicum infections in China.

This paper reports the results of the dot enzyme-linked immunosorbent assay (dot-ELISA) for the serological diagnosis of 50 acute and 50 chronic Schistosoma japonicum-infected patients employing keyhole limpet haemocyanin (KLH) and soluble egg antigen (SEA) as the specific antigens. The sensitivity of both antigens for the detection of both forms of this infection was 100% and 90%, respectively, using a test serum dilution of 1:100. When the serum dilution was adjusted to 1:500, the sensitivity of the KLH dot-ELISA was 82% and 15%, respectively. Thus, the different manifestations of this disease can be easily distinguished. None of the 44 uninfected control sera gave a positive result with the KLH dot-ELISA, though 6 (14%) did so with the SEA dot-ELISA. Cross reactivity rates of 13% and 23% were observed for clonorchiasis (n = 30) and paragonimiasis (n = 22). Therefore, the overall diagnostic effectiveness of both the KLH dot-ELISA and SEA dot-ELISA for the detection of S. japonicum infection in endemic regions in China was 97% and 92%, respectively.

[A study of classification and treatment of combined traditional Chinese medicine and Western medicine of 69 cases of aplastic anemia].

Hemopoietic progenitor cells (BFU-E, CFU-E and CFU-GM) of 69 cases of aplastic anemia were cultured in vitro while the sensitivity of CFU-E and BFU-E to androgen was assayed. The suppressive effect of peripheral blood mononuclear cell (PBMNC) from patients on normal CFU-GM growth was also studied. Hence 69 cases of aplastic anemia were divided into three types: 10 cases of stem cell deficiency type, 30 cases of immuno-mediated type and 29 cases of androgen response type. According to above classification, different treatment programs were practiced using both TCM and western medicine. In the androgen response type, androgen and TCM were used and the effective rate reached 92.3%. In the immuno-mediated type, in addition to TCM. Immunosuppressive agents were cautiously used and the effective rate was 70.6%. As for the stem cell deficiency type, 10 patients' conditions were usually very severe so comprehensive therapeutical means were adopted and 3 cases were improved. The overall response rate of these three was 73.2%. These results showed that the treatment program under the direction of classification have greatly improved the curative effect.

A new method to quantify the inoculum potential of arbuscular mycorrhizal fungi.

Previously described concepts of inoculum potential (IP) and methods to measure the IP of arbuscular mycorrhizal fungi (AMF) are reviewed. The concept of IP is elusive and needs developing- A new definition of IP is described here us the number of viable fungal propagules and structures coupled with their initial infectivity, and the IP can be calculated from the formula IP =(N × H × K)+S or IP = (N × L) +S, where N= numbers of vesicles in roots and points of hyphae connected with the roots per unit length of the roots; W= root weight; K= root length per unit weight of the roots; L= root length: S= numbers of viable spores in an inoculum. For the AMF that product spores in roots, few spores, or no spares, the formula becomes IP =N × W × K = N × L. The parameter of the IP is therefore the total numbers of vesicles and/or spores in roots, points of hyphae connected with roots, and viable spores in an inoculum of any type. The correlation coefficients between the IP of the inoculum of Glamus Mossear (Nicol. &Gerd.) Gerdemann &Trappe, Glomus versiforme (Karsten) Berth,or Sclerocystis sinuosa Gerdemann &Bakhi and the amount of early stage infection produced by the corresponding were all > 0.93 (P < 0.01)on three host plants. Gassypium hirsutum L., or Sarghum Sudanense L., It is suggested that the IP should be easily and rapidly estimated with accuracy by the present method.

[Correlation between traditional Chinese medicine classification of 53 patients with aplastic anemia and varieties of hemopoietic progenitor cells in vitro culture].

Aplastic anemia can be classified distinctively three types as progenitor depletive; immunosuppressive and androgenic sensitive. Using bone marrow culture in vitro which had been accomplished in our laboratory, 53 patients with aplastic anemia were also classified according to TCM term in three groups as Yin deficiency, Yang deficiency and both Yin and Yang deficiency, and the correlation was observed between TCM classification and lab character of these patients. The results showed that the number of CFU-GM, CFU-E and BFU-E in Yang deficiency group was significantly higher than that in the other two groups (P less than 0.01 and P less than 0.05). It also showed that the sensitivity of progenitor cells to androgenic hormones of Yang deficiency group was preferential to all (P less than 0.005 and P less than 0.05). The percentage of immunosuppressive type of aplastic anemia in Yin deficiency group was much higher than those in the other two groups (P less than 0.005). These observations suggested that TCM classification for aplastic anemia in this paper has objective material foundation.