|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Folic acid supplementation inhibits recurrence of colorectal adenomas:A randomized chemoprevention trial显示文摘AIM: To determine whether folic acid supplementation will reduce the recurrence of colorectal adenomas, the precursors of colorectal cancer, we performed a double-blind placebo-controlled trial in patients with adenomatous polyps. METHODS: In the current double-blind, placebo-controlled trial at this VA Medical Center, patients with colorectal adenomas were randomly assigned to receive either a daily 5 mg dose of folic acid or a matched identical placebo for 3 years. All polyps were removed at baseline colonoscopy and each patient had a follow up colonoscopy at 3 years. The primary endpoint was a reduction in the number of recurrent adenomas at 3 years. RESULTS: Of 137 subjects, who were eligible after confirmation of polyp histology and run-in period to conform compliance, 94 completed the study; 49 in folic acid group and 45 in placebo group. Recurrence of adenomas at 3-year was compared between the two groups. The mean number of recurrent polyps at 3-year was 0.36 (SD, 0.69) for folic acid treated patients compared to 0.82 (SD, 1.17) for placebo treated subjects, resulting in a 3-fold increase in polyp recurrence in the placebo group. Patients below 70 years of age and those with left-sided colonicadenomas or advanced adenomas responded better to folic acid supplementation. CONCLUSION: High dose folic acid supplementation is associated with a signif icant reduction in the recurrence of colonic adenomas suggesting that folic acid may be an effective chemopreventive agent for colorectal neoplasia. | Richard Jaszewski Sabeena Misra Martin Tobi Nadeem Ullah Jo Ann Naumoff Omer Kucuk Edi Levi Bradley N Axelrod Bhaumik B Patel Adhip PN Majumdar | 2008 | World Journal of Gastroenterology2008，14，28： | 10 |
| 2 | AIMS65: A promising upper gastrointestinal bleeding risk score but further validation required显示文摘A novel upper gastrointestinal bleeding risk stratification score(AIMS65) has recently been developed and validated. It has advantages over existing risk scores including being easy to remember and lack of subjectivity in calculation. We comment on a recent study that has cast doubt on the applicability of AIMS65 in the peptic ulcer disease population. Although promising, further studies are required to evaluate the validity of AIMS65 in various populations. | Ray Boyapati Avik Majumdar Marcus Robertson | 2014 | World Journal of Gastroenterology2014，20，39： | 7 |
| 3 | Antimicrobial activity of Cannabis sativa,Thuja orientalis and Psidium guajava leaf extracts against methicillin-resistant Staphylococcus aureus显示文摘Objective: This study examined the antimicrobial activity of Cannabis sativa, Thuja orientalis and Psidium guajava against methicillin-resistant Staphylococcus aureus(MRSA) and used a standardized purification protocol to determine the presence and abundance of bioactive compounds in the leaf extracts.Methods: In vitro antimicrobial activities of the ethanolic extracts of C. sativa, T. orientalis and P. guajava were tested against MRSA. The presence of bioactive molecules in these three leaves was evaluated using biochemical assays and high-performance thin-layer chromatography(HPTLC).Results: Resistance to methicillin, penicillin, oxacillin and cefoxitin was observed in each of the clinical and nonclinical MRSA isolates. However, they were still vulnerable to vancomycin. Used individually,the 50% extract of each plant leaf inhibited MRSA growth. A profound synergism was observed when C. sativa was used in combination with T. orientalis(1:1) and when P. guajava was used in combination with T. orientalis(1:1). This was shown by larger zones of inhibition. This synergism was probably due to the combined inhibitory effect of phenolics present in the leaf extracts(i.e., quercetin and gallic acid)and catechin, as detected by HPTLC.Conclusion: The leaf extracts of C. sativa, T. orientalis and P. guajava had potential for the control of both hospital-and community-acquired MRSA. Moreover, the inhibitory effect was enhanced when extracts were used in combination. | Shohini Chakraborty Nashra Afaq Neelam Singh Sukanta Majumdar | 2018 | Journal of Integrative Medicine2018，16，5： | 7 |
| 4 | The crystal structure of the non-liganded 14-3-3σ protein: insights into determinants of isoform specific ligand binding and dimerization显示文摘Seven different, but highly conserved 14-3-3 proteins are involved in diverse signaling pathways in human cells. It isunclear how the 14-3-3σ isoform, a transcriptional target of p53, exerts its inhibitory effect on the cell cycle in thepresence of other 14-3-3 isoforms, which are constitutively expressed at high levels. In order to identify structuraldifferences between the 14-3-3 isoforms, we solved the crystal structure of the human 14-3-3σ protein at a resolutionof 2.8 ? and compared it to the known structures of 14-3-3ζ and 14-3-3τ. The global architecture of the 14-3-3σ foldis similar to the previously determined structures of 14-3-3ζ and 14-3-3τ: two 14-3-3σ molecules form a cup-shapeddimer. Significant differences between these 14-3-3 isoforms were detected adjacent to the amphipathic groove, whichmediates the binding to phosphorylated consensus motifs in 14-3-3-ligands. Another specificity determining region islocalized between amino-acids 203 to 215. These differences presumably select for the interaction with specific ligands,which may explain the different biological functions of the respective 14-3-3 isoforms. Furthermore, the two 14-3-3σmolecules forming a dimer differ by the spatial position of the ninth helix, which is shifted to the inside of the ligandinteraction surface, thus indicating adaptability of this part of the molecule. In addition, 5 non-conserved residues arelocated at the interface between two 14-3-3σ proteins forming a dimer and represent candidate determinants of homo-and hetero-dimerization specificity. The structural differences among the 14-3-3 isoforms described here presumablycontribute to isoform-specific interactions and functions. | Anne BENZINGER Grzegorz M. POPOWICZ Joma K. JOY Sudipta MAJUMDAR Tad A. HOLAK Heiko HERMEKING | 2005 | Cell Research2005，15，4： | 6 |
| 5 | Viral degradasome hijacks mitochondria to suppress innate immunity显示文摘在主人和病原体的能力的天生的免疫之间的平衡影响致病和毒力强烈躲避它。二 nonstructural (NS ) 蛋白质, NS1 和 NS2,呼吸 syncytial,病毒(RSV ) 极其为 RSV 被要求毒力。一起,他们强烈压制类型我干扰素(IFN ) 调停了由降级或禁止多重细胞的因素的主人房间的天生的免疫为 IFN 正式就职或反应要求了小径包括 RIG-I, IRF3, IRF7, TBK1 和 STAT2。这里,我们为 NS 蛋白质装配的大、异构的 degradative 建筑群的存在提供证据,我们把它称为 “ NS-degradasome”(NSD ) 。NSD 是粗略地,在尺寸的 ~ 300-750 kD,和它的 degradative 活动被净化的线粒体的增加在 vitro 提高。在房间, NS 蛋白质的多数和到在 RSV 感染之上的线粒体的 NSD translocated 的底层内。基因并且药理学证据证明天生的豁免的最佳的抑制要求 mitochondrial MAVS 和 mitochondrial 活动性。一起,我们建议在的一个新奇范例线粒体,知道为主人的天生的有免疫力的激活重要,为天生的免疫的病毒的抑制也是重要的。 | Ramansu Goswami Tanmay Majumdar Jayeeta Dhar Saurabh Chattopadhya3~ Sudip K Bandyopadhyay Valentina Verbovetskaya Ganes C Sen Sailen Barik | 2013 | Cell Research2013，23，8： | 6 |
| 6 | Design and analysis of extended depth of focus metalenses for achromatic computational imaging显示文摘Metasurface optics have demonstrated vast potential for implementing traditional optical components in an ultracompact and lightweight form factor.Metasurfaces,however,suffer from severe chromatic aberrations,posing serious limitations on their practical use.Eixisting approaches for circumventing this involving dispersion engineering are limited to small apertures and often entail multiple scatterers per unit cell with small feature sizes.Here,we prescnt an alternative technique to mitigatc chromatic aberration and demonstrate high-quality,full-color imaging using extended depth of focus(EDOF)metalenses and computational reconstruction.Previous EDOF metalenses have relied on cubic phase masks,where the image quality suffers from asymmetric artefacts.Here we demonstrate the use of rotationally symmetric masks,including logarithmic-aspherical,and shifted axicon masks,to mitigate this problem.Our work will inspire further development in achromatic metalenses beyond dispersion engineering and hybrid optical-digital metasurface systems. | LUOCHENG HUANA JAMES WHITEHEAD SHANE COLBURN ARKA MAJUMDAR | 2020 | Photonics Research2020，8，10： | 5 |
| 7 | Cancer stem cells in Helicobacter pylori infection and aging: Implications for gastric carcinogenesis显示文摘AIM: To demonstrated the combined effects of aging and carcinogen treatment on cancer stem/stem-like cells(CSCs) of gastric mucosa in an animal model. METHODS: In this study we investigated the effects of aging and Helicobacter pylori(H. pylori) inflammation as a model for inflammation induced carcinogenesis in human and rat gastric mucosa samples. In aging studies, we compared 4-mo old(young) with 22 mo(aged) old Fischer-344 rats. For human studies, gastric biop-sies and resection specimens representing normal mucosa or different stages of H. pylori gastritis and gastric adenocarcinomas were used for determining the expression of stem cell markers CD166, ALDH1 and LGR5. In addition we performed immunofluorescent double labeling for B-catenin and Lgr5 in both rat and human gastric tissues to examine the status of Wnt signaling in these cells. RESULTS: CSC markers ALDH1, LGR5, and CD166 were expressed in very low levels in normal human gastric mucosa or young rat gastric mucosa. In contrast, level of expression for all three markers significantly increased in H. pylori gastritis and gastric adenocarcinomas as well as in normal gastric mucosa in aged rats. We also observed cytoplasmic B-catenin staining in both aged rat and human H. pylori inflamed gastric mucosa, which were found to be colocalized with Lgr5 immunoreactive cells. The increased number of ALDH1, CD166 and LGR5 positive cells in H. pylori gastritis indicates that increased number of stem-like cells in gastric mucosa is an early event, and may constitute an important step in the progression to neoplasia. CONCLUSION: Our observation of the age-related increase in cancer stem/stem-like cells in the gastric mucosa may explain the increased incidence of gastric cancer during aging. Combination of aging and H. pylori infection may have additive effects in progression to neoplasia. | Edi Levi Paula Sochacki Nabiha Khoury Bhaumik B Patel Adhip PN Majumdar | 2014 | World Journal of Gastrointestinal Pathophysiology2014，5，3： | 5 |
| 8 | L-Plastin deficiency produces increased trabecular bone due to attenuation of sealing ring formation and osteoclast dysfunction显示文摘Bone resorption requires the formation of complex, actin-rich cytoskeletal structures. During the early phase of sealing ring formation by osteoclasts, L-plastin regulates actin-bundling to form the nascent sealing zones(NSZ). Here, we show that L-plastin knockout mice produce osteoclasts that are deficient in the formation of NSZs, are hyporesorptive, and make superficial resorption pits in vitro. Transduction of TAT-fused full-length L-plastin peptide into osteoclasts from L-plastin knockout mice rescued the formation of nascent sealing zones and sealing rings in a time-dependent manner. This response was not observed with mutated full-length L-plastin(Ser-5 and-7 to Ala-5 and-7) peptide. In contrast to the observed defect in the NSZ, L-plastin deficiency did not affect podosome formation or adhesion of osteoclasts in vitro or in vivo. Histomorphometry analyses in 8-and 12-week-old female L-plastin knockout mice demonstrated a decrease in eroded perimeters and an increase in trabecular bone density, without a change in bone formation by osteoblasts. This decrease in eroded perimeters supports that osteoclast function is attenuated in L-plastin knockouts. Micro-CT analyses confirmed a marked increase in trabecular bone mass. In conclusion, female L-plastin knockout mice had increased trabecular bone density due to impaired bone resorption by osteoclasts. L-plastin could be a potential target for therapeutic interventions to treat trabecular bone loss. | Meenakshi AChellaiah Megan CMoorer Sunipa Majumdar Hanan Aljohani Sharon CMorley Vanessa Yingling Joseph PStains | 2020 | Bone Research2020，8，1： | 4 |
| 9 | Emerging therapies in gastrointestinal cancers显示文摘Members of the receptor tyrosine kinase family, that include EGFR, ErbB-2/HER-2, ErbB-3/HER-3 and ErbB-4/ HER-4, are frequently implicated in experimental models of epithelial cell neoplasia as well as in human cancers. Therefore, interference with the activation of these growth factor receptors represents a promising strategy for de- velopment of novel and selective anticancer therapies. Indeed, a number of inhibitors that target either EGFR or HER-2, with the exception of a few that target both; have been developed for treatment of epithelial cancers. Since most solid tumors express different ErbB receptors and/or their ligands, identification of inhibitor(s), targeting multiple EGFR family members may provide a therapeutic benefit to a broader patient population. Here we describe the significance of an ErbB family of receptors in epithelial cancers, and summarize different available therapeutics targeting these receptors. It also emphasizes the need to develop pan-ErbB inhibitors and discusses EGF-Receptor Related Protein, a recently isolated negative regulator of EGFR as a potential pan-ErbB therapeutic for a wide vari- ety of epithelial cancers. | Jyoti Nautiyal Arun K Rishi Adhip PN Majumdar | 2006 | World Journal of Gastroenterology2006，12，46： | 4 |
| 10 | Tree species diversity and stand structure along major community types in lowland primary and secondary moist deciduous forests in Tripura,Northeast India显示文摘Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura.Overall 10,957 individual trees belonging to 46 family,103 genera and 144 species were counted at ≥30 cm DBH(diameter at breast height) using 28 permanent belt transects with a size of 1 ha(10 m × 1000 m).Four different tree communities were identified.The primary forests was dominated by Shorea robusta(mean density 464.77 trees ha-1,105 species) and Schima wallichii(336.25 trees ha-1,82 species),while the secondary forests was dominated by Tectona grandis(333.88 trees ha-1,105 species) and Hevea brasiliensis(299.67 trees ha-1,82 species).Overall mean basal area in this study was 18.01m 2 ·ha-1 ;the maximum value was recorded in primary Shorea forest(26.21 m 2 ·ha-1).Mean density and diversity indices were differed significantly within four different communities.No significant differences were observed in number of species,genera,family and tree basal cover area.Significant relationships were found between the species richness and different tree population groups across the communities.Results revealed that species diversity and density were increased in those forests due to past disturbances which resulted in slow accumulation of native oligarchic small tree species.Seventeen species were recorded with <2 individuals of which Saraca asoka(Roxb.) de Wilde and Entada phaseoloides(L.) Merr.etc.extensively used in local ethno-medicinal formulations.The present S.robusta Gaertn dominated forest was recorded richer(105 species) than other reported studies.Moraceae was found more speciose family instead of Papilionaceae and Euphorbiaceae than other Indian moist deciduous forests.Seasonal phenological gap in such moist deciduous forests influenced the population of Trachypithecus pileatus and capped langur.The analysis of FIV suggested a slow trend of shifting the population of Lamiaceae group by Moraceae species in secondary T.grandis L.dominated community. | Koushik Majumdar Uma Shankar Badal Kumar Datta | 2012 | Journal of Forestry Research2012，23，4： | 4 |
| 11 | Binding interaction of phosphorus heterocycles with bovine serum albumin:A biochemical study显示文摘Interaction between bovine serum albumin(BSA) and phosphorus heterocycles(PHs) was studied using multispectroscopic techniques. The results indicated the high binding affinity of PHs to BSA as it quenches the intrinsic fluorescence of BSA. The experimental data suggested the fluorescence quenching mechanism between PHs and BSA as a dynamic quenching. From the UV–vis studies, the apparent association constant(K_(app)) was found to be 9.25×10~2, 1.27×10~4and 9.01×10~2L/mol for the interaction of BSA with PH-1, PH-2 and PH-3,respectively. According to the F?rster's non-radiation energy transfer(FRET) theory, the binding distances between BSA and PHs were calculated. The binding distances(r) of PH-1, PH-2 and PH-3 were found to be2.86, 3.03, and 5.12 nm, respectively, indicating energy transfer occurs between BSA and PHs. The binding constants of the PHs obtained from the fluorescence quenching data were found to be decreased with increase of temperature. The negative values of the thermodynamic parameters ΔH, ΔS and ΔG at different temperatures revealed that the binding process is spontaneous; hydrogen bonds and van der Waals interaction were the main force to stabilize the complex. The microenvironment of the protein-binding site was studied by synchronous fluorescence and circular dichroism(CD) techniques and data indicated that the conformation of BSA changed in the presence of PHs. Finally, we studied the BSA-PHs docking using Auto Dock and results suggest that PHs is located in the cleft between the domains of BSA. | Swarup Roy Raj Kumar Nandi Sintu Ganai K.C. Majumdar Tapan K. Das | 2017 | Journal of Pharmaceutical Analysis2017，7，1： | 4 |
| 12 | 结肠癌复发的规定和治疗学的策略的开发显示文摘 Recurrence of colon cancer still remains a major issue which affects nearly 50% of patients treated by conventional therapeutics. Although the underlying causative factor(s) is not fully understood, development of drug-resistance has been associated with induction of cancer stem or stem-like cells (CSCs) which constitute a small sub-population of tumor cells known to be highly resistant to chemotherapy. In fact, the discovery of CSCs in a variety of tumors (including colon cancer) has changed the view of carcinogenesis and therapeutic strategies. Emerging reports have indicated that to improve patient outcomes, conventional anticancer therapies should be replaced with specifi c approaches targeting CSCs. Thus, therapeutic strategies that specifically target CSCs are being sought to reduce the risk of relapse and metastasis. In order to specifi cally target colon CSCs (while sparing somatic intestinal stem cells), it is critical to identify unique deregulated pathways responsible for self-renewal of CSCs and colon cancer recurrence. Colon CSCs present a unique opportunity to better understand the biology of solid tumors. Thus, a better understanding of the clinical signs and symptoms of colon cancer patients (under-going surgery or chemotherapy) during perioperative periods, along with the underlying regulatory events affecting the stem/progenitor cell self-renewal and differentiation of colon epithelial cells, is of immense importance. In this review we discuss the implication of clinical factors and the emerging role of CSCs during recurrence of colon cancer along with the development of new therapeutic strategies involving the use of natural agents. | Shailender Singh Kanwar Anuradha Poolla Adhip PN Majumdar | 2012 | World Journal of Gastrointestinal Pathophysiology2012，3，1： | 3 |
| 13 | Metabolic associated fatty liver disease:Addressing a new era in liver transplantation显示文摘Metabolic associated fatty liver disease(MAFLD),previously termed nonalcoholic fatty liver disease,is the leading global cause of liver disease and is fast becoming the most common indication for liver transplantation.The recent change in nomenclature to MAFLD refocuses the conceptualisation of this disease entity to its metabolic underpinnings and may help to spur a paradigm shift in the approach to its management,including in the setting of liver transplantation.Patients with MAFLD present significant challenges in the pre-,peri-and posttransplant settings,largely due to the presence of medical comorbidities that include obesity,metabolic syndrome and cardiovascular risk factors.As the community prevalence of MAFLD increases concurrently with the obesity epidemic,donor liver steatosis is also a current and future concern.This review outlines current epidemiology,nomenclature,management issues and outcomes of liver transplantation in patients with MAFLD. | Madeleine G Gill Avik Majumdar | 2020 | World Journal of Hepatology2020，12，12： | 3 |
| 14 | In Vitro Nicotine-Induced Oxidative Stress in Mice Peritoneal Macrophages: A Dose-Dependent Approach显示文摘 | Santanu Kar Mahapatra Subhasis Das Surajit Bhattacharjee N. Gautam Subrata Majumdar Somenath Roy | 2009 | Toxicology Mechanisms and Methods2009，，2： | 3 |
| 15 | Gut microbiome profiling and colorectal cancer in African Americans and Caucasian Americans显示文摘AIM To determine whether and to what extent the gut microbiome is involved in regulating racial disparity in colorectal cancer(CRC). METHODS All patients were recruited and experiments were performed in accordance with the relevant guidelines and regulations by the Institutional Review Boards (IRB), committees of the John D. Dingell VAMC and Wayne State University guidelines. African American (AA) and Caucasian American (CA) patients were scheduled for an outpatient screening for colonoscopy, and no active malignancy volunteer patients were doubly consented, initially by the gastroenterologist and later by the study coordinator, for participation in the study. The gut microbial communities in colonic effluents from AAs and CAs were examined using 16 sRNA profiling, and bacterial identifications were validated by performing SYBR-based Real Time PCR. For metagenomic analysis to characterize the microbial communities, multiple software/tools were used, including Metastats and R statistical software.RESULTS It is generally accepted that the incidence and mortality of CRC is higher in AAs than in CAs. However, the reason for this disparity is not well understood. We hypothesize that the gut microbiome plays a role in regulating this disparity. Indeed, we found significant differences in species richness and diversity between AAs and CAs. Bacteroidetes was more abundant in AAs than in CAs. In particular, the pro-inflammatory bacteria Fusobacterium nucleatum and Enterobacter species were significantly higher in AAs, whereas probiotic Akkermansia muciniphila and Bifidobacterium were higher in CAs. The polyphyletic Clostridia class showed a divergent pattern, with Clostridium XI elevated in AAs, and Clostridium IV, known for its beneficial function, higher in CAs. Lastly, the AA group had decreased microbial diversity overall in comparison to the CA group. In summary, there were significant differences in pro-inflammatory bacteria and microbial diversity between AA and CA, which may help explain the CRC disparity between groups.CONCLUSION Our current investigation, for the first time, demonstrates microbial dysbiosis between AAs and CAs, which could contribute to the racial disparity of CRC. | Lulu Farhana Fadi Antaki Farhan Murshed Hamidah Mahmud Stephanie L Judd Pratima Nangia-Makker Edi Levi Yingjie Yu Adhip PN Majumdar | 2018 | World Journal of Gastrointestinal Pathophysiology2018，9，2： | 3 |
| 16 | An unusual cause of dyspnoea complicating right upper abdominal swelling显示文摘一中年,恰好上面的腹的疼痛地介绍的非瘾君子男性并且与呼吸窘迫胀大。检查揭示了中央青紫,两足动物 pitting 与突出腹上部并且背静脉。肝被扩大,温柔,没有任何脾大或腹水,跨越了 20 厘米。另外的系统是临床上正常的。实验室调查证明有稍微捣乱的肝的 polymorphonuclear 白细胞增多工作。腹的 ultrasonography 与压缩劣等的静脉腔(IVC ) 在肝的正确脑叶显示出脓肿,中间、左的肝的静脉。动脉的血气体(ABG ) 与 orthodeoxia 记录了组织缺氧,空气对比回响心动描记法肺内分流是暗示的。hepato 肺的症候群(HPS ) 的诊断与对阿米巴的肝脓肿第二等的近正常的肝功能被做。它颠倒了肝脓肿的完全后面的成功的处理。 | Sanjay Kumar Mandal Partha Pratim Chakraborty Rana Bhattacharjee Subhasis Roy Chowdhury Shounak Majumdar | 2006 | World Journal of Gastroenterology2006，12，25： | 3 |
| 17 | Sunflower response to potassium fertilization and nutrient requirement estimation显示文摘Field experiments were conducted in oil and edible sunflower to study the effects of potassium(K) fertilization on achene yield and quality, and to estimate the nutrient internal efficiency(IE) and nutrient requirement in sunflower production. All trials in edible sunflower and 75% trials in oil sunflower showed positive yield responses to K fertilization. Compared with control without K fertilization, the application of K increased achene yield by an average of 406 kg ha^(–1) for oil sunflower and 294 kg ha^(–1) for edible sunflower. K application also increased 1 000-achene weight and kernel rate of both oil and edible sunflower. K fertilization improved the contents of oil, oleic acid, linoleic acid and linolenic acid in achenes of oil sunflower, and increased contents of oil, total unsaturated fatty acid and protein in achenes of edible sunflower. The average agronomic efficiency of K fertilizer was 4.0 for oil sunflower and 3.0 kg achene kg^(–1) K_2O for edible sunflower. The average IE of N, P and K under balanced NPK fertilization was 22.9, 82.8, and 9.9 kg kg^(–1) for oil sunflower, and 27.3, 138.9, and 14.3 kg kg^(–1) for edible sunflower. These values were equivalent to 45.5, 14.1, and 108.1 kg, and 39.0, 8.0, and 71.7 kg of N, P and K, respectively, in above-ground dry matter required for production per ton of achenes. The average harvest index of N, P and K was 0.47, 0.56 and 0.05 kg kg^(–1) in oil sunflower, and 0.58, 0.58 and 0.14 kg kg^(–1) in edible sunflower. | LI Shu-tian DUAN Yu GUO Tian-wen ZHANG Ping-liang HE Ping Kaushik Majumdar | 2018 | Journal of Integrative Agriculture2018，17，12： | 3 |
| 18 | Free-space optical neural network based on thermal atomic nonlinearity显示文摘As artificial neural networks(ANNs)continue to make strides in wide-ranging and diverse fields of technology,the search for more efficient hardware implementations beyond conventional electronics is gaining traction.In particular,optical implementations potentially offer extraordinary gains in terms of speed and reduced energy consumption due to the intrinsic parallelism of free-space optics.At the same time,a physical nonlinearity—a crucial ingredient of an ANN—is not easy to realize in free-space optics,which restricts the potential of this platform.This problem is further exacerbated by the need to also perform the nonlinear activation in parallel for each data point to preserve the benefit of linear free-space optics.Here,we present a free-space optical ANN with diffraction-based linear weight summation and nonlinear activation enabled by the saturable absorption of thermal atoms.We demonstrate,via both simulation and experiment,image classification of handwritten digits using only a single layer and observed 6% improvement in classification accuracy due to the optical nonlinearity compared to a linear model.Our platform preserves the massive parallelism of free-space optics even with physical nonlinearity,and thus opens the way for novel designs and wider deployment of optical ANNs. | Albert Ryou James Whitehead Maksym Zhelyeznyakov Paul Anderson Cem Keskin Michal Bajcsy Arka Majumdar | 2021 | Photonics Research2021，9，4： | 2 |
| 19 | Total ionizing dose effects on graphene-based charge-trapping memory显示文摘This study investigates the total ionizing dose effects in graphene-based charge-trapping memory(GCTM) capacitors by using60 Co γ-irradiation. Electrical properties including C-V hysteresis window,gate leakage current, and flat band voltage shifts are evaluated with ionizing dose levels up to 1 Mrad(Si).The C-V hysteresis memory window is hardly affected by the irradiation. The gate leakage current increases with the increase of ionizing dose due to the multiple-trap assisted tunneling mechanism. Significant electrical degrade of the devices in programmed and erased states has been observed with the increase of the dose levels. Mechanisms behind the degradation are attributed to the photo-emission in the graphene nanodisc charge-trapping sets, radiation-induced holes trapping in the peripheral oxides, and the recombination of the stored electrons with the radiation-induced holes. | Kai XI Jinshun BI Sandip MAJUMDAR Bo LI Jing LIU Yannan XU Ming LIU | 2019 | Science China(Information Sciences)2019，62，12： | 2 |
| 20 | Politics, information and the urban bias显示文摘 | Sumon Majumdar Anandi Mani Sharun W. Mukand | | Journal of Development Economics0，，： | 2 |
您所在的机构暂未开通此部分的功能，请联系管理员