Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wave...Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wavelength division multiplexing silicon photonics receiver chip composed of an arrayed waveguide grating and Ge-on-Si photodetectors. Integrated inductors are introduced to enhance the high-speed performance of photodetectors, enabling data rates up to 112 Gbps with high responsivity and low dark current. The operating wavelength range of the arrayed wavelength grating is adjusted according to the response of the Ge-on-Si photodetector. The optical insertion loss, cross talk and central wavelength of the array waveguide grating are 2.1 to 3.7 d B,-12 to-15 d B, and 1538 nm, respectively. The proposed receiver chip offers a solution to meet the challenges of modern data transmission requirements.展开更多
A silicon-based germanium(Ge)photodetector working for C and L bands is proposed in this paper.The device fea-tures a novel asymmetric PIN structure,which contributes to a more optimized electric field distribution in...A silicon-based germanium(Ge)photodetector working for C and L bands is proposed in this paper.The device fea-tures a novel asymmetric PIN structure,which contributes to a more optimized electric field distribution in Ge and a shorter effective width of depleted region.Meanwhile,the optical structure is designed carefully to enhance responsivity for broad-band.Under-7 V,where the weak avalanche process happens,the responsivity of our device is 1.49 and 1.16 A/W at 1550 and 1600 nm,with bandwidth of 47.1 and 44.5 GHz,respectively.These performances demonstrate the significant application poten-tial of the device in optical communication systems.展开更多
Nucleotide-binding and oligomerization domain 2(NOD2),a member of the NOD protein family,plays an important role in innate immunity.In response to pathogen attack,NOD2 stimulates cytokine and defensin production by ac...Nucleotide-binding and oligomerization domain 2(NOD2),a member of the NOD protein family,plays an important role in innate immunity.In response to pathogen attack,NOD2 stimulates cytokine and defensin production by activating nuclear factor(NF)-kB,a key transcription factor responsible for mediating downstream reactions.However,the mechanism linking NOD2 regulation and NF-kB activation is poorly understood.Using bioinformatics,we found a completely preserved canonical NF-kB binding site in the NOD2 core promoter(216 to 225 bp)in both humans and chimpanzees.The functional role of this NF-kB binding site was investigated using the enhanced green fluorescent protein(EGFP)reporter system,site-directed mutagenesis,the NF-kB activation inhibitor(JSH-23)and the chromatin immunoprecipitation(ChIP)assay.The results show that the NF-kB binding site is critical for regulation of the NOD2 gene.Either deletion of the NF-kB binding elements within the NOD2 promoter or treatment with an NF-kB activation inhibitor could lead to a significant loss of NOD2 promoter activity as detected by reporter gene assay.The canonical NF-kB binding site was bound by NF-kB as determined by the ChIP method.Based on these results,we suggest a positive feedback regulation between NF-kB and NOD2,which may represent an efficient mechanism in response to pathogen invasion.展开更多
Uric acid(UA)is a key intermediate in purine degradation across diverse organisms,while its accumulation in humans leads to inflammation and gout disease.Aerobic organisms degrade UA via a well-known“oxidative pathwa...Uric acid(UA)is a key intermediate in purine degradation across diverse organisms,while its accumulation in humans leads to inflammation and gout disease.Aerobic organisms degrade UA via a well-known“oxidative pathway”involving dearomatization of the purine core catalyzed by UA oxidases or dehydrogenases.The ability to degrade UA is also widespread in anaerobic bacteria,including gut bacteria,although the mechanisms are incompletely understood.Here,we report the biochemical characterization of a recently identified UA degradation gene cluster from Escherichia coli,and show that it encodes a“reductive pathway”for UA degradation.In this pathway,UA is first reduced to 2,8-dioxopurine(yanthine)by a xanthine dehydrogenase homolog(XdhD),followed by dearomatization of the purine core catalyzed by a flavin-dependent reductase(YgfK).Stepwise cleavage of the pyrimidine and imidazole rings forms 2,3-diureidopropionate,and stepwise cleavage of the 2-and 3-ureido groups then forms 2,3-diaminopropionate,which is cleaved by a pyridoxal 5′-phosphate-dependent lyase(YgeX)to pyruvate and ammonia.The detection of yanthine in clinical serum samples from healthy individuals and significantly higher levels from gout patients suggests that yanthine is a physiologically relevant circulating metabolite.A probiotic E.coli Nissle strain was engineered for constitutive overexpression of the gene cluster,and oral administration in a uricase-knockout hyperuricemic mouse model significantly reduced the serum UA level and alleviated associated kidney injury,suggesting a potential route towards uricolytic probiotics.展开更多
The care of obstetrics patients has improved dramatically over the past few decades.Unfortunately,rates of cesarean section remain high,and decreasing this rate requires close care and follow-up in the prenatal outpat...The care of obstetrics patients has improved dramatically over the past few decades.Unfortunately,rates of cesarean section remain high,and decreasing this rate requires close care and follow-up in the prenatal outpatient setting.Counseling regarding cesarean delivery and vaginal delivery is imperative.Opportunities still exist in helping patients objectively weigh the decision for cesarean delivery versus vaginal delivery.Additional developments have occurred in the intrapartum and the postpartum setting,with an aim to improve patient and neonatal outcomes.Changes have been implemented for patients undergoing cesarean delivery including preoperative and intraoperative treatment of pain,nausea,and vomiting,as well as postoperative care bundles that improve patient outcomes.Innovations have also occurred in the care of postpartum patients after vaginal delivery,again with improvements in patient outcomes.This article summarizes the current evidence,provides care recommendations,and identifies the next steps in improving obstetrics care.展开更多
The 2μm wavelength band emerges as a promising candidate for the next communication window to enhance the transmission capacity of data.A high-responsivity and high-speed photodetector operating at 2μm is crucial fo...The 2μm wavelength band emerges as a promising candidate for the next communication window to enhance the transmission capacity of data.A high-responsivity and high-speed photodetector operating at 2μm is crucial for the 2-μm-wavelength-band communication system.Here,we present an on-chip waveguide-coupled germanium photodetector with remarkably high responsivity and data-receiving rate,employing subbandgap light absorption and avalanche multiplication.The device is designed with an ingenious and simple asymmetric lateral p-i-n junction structure and fabricated through a standard CMOS process by a commercial factory.It has a responsivity of 3.64 A/W and a maximum bandwidth of 50 GHz at 2μm wavelength.For the first time,to the best of our knowledge,an optical receiving rate of up to 112 Gbps is demonstrated at 2μm,verifying its feasibility in a highspeed 2-μm-band communication system.To the best of our knowledge,the proposed device stands out as the fastest photodiode with the highest responsivity among all group III-V and group IV photodetectors working in the 2μm wavelength band.展开更多
基金National Key Research and Development Program of China (2022YFB2802400)National Natural Science Foundation of China (62250010, 62090054, 62274160)Youth Innovation Promotion Association of the Chinese Academy of Sciences (2021111)。
文摘Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wavelength division multiplexing silicon photonics receiver chip composed of an arrayed waveguide grating and Ge-on-Si photodetectors. Integrated inductors are introduced to enhance the high-speed performance of photodetectors, enabling data rates up to 112 Gbps with high responsivity and low dark current. The operating wavelength range of the arrayed wavelength grating is adjusted according to the response of the Ge-on-Si photodetector. The optical insertion loss, cross talk and central wavelength of the array waveguide grating are 2.1 to 3.7 d B,-12 to-15 d B, and 1538 nm, respectively. The proposed receiver chip offers a solution to meet the challenges of modern data transmission requirements.
基金supported by National Key Research and Development Program of China(2022YFB2802400)National Natural Science Foundation of China(62250010,62090054,62274160)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021111).
文摘A silicon-based germanium(Ge)photodetector working for C and L bands is proposed in this paper.The device fea-tures a novel asymmetric PIN structure,which contributes to a more optimized electric field distribution in Ge and a shorter effective width of depleted region.Meanwhile,the optical structure is designed carefully to enhance responsivity for broad-band.Under-7 V,where the weak avalanche process happens,the responsivity of our device is 1.49 and 1.16 A/W at 1550 and 1600 nm,with bandwidth of 47.1 and 44.5 GHz,respectively.These performances demonstrate the significant application poten-tial of the device in optical communication systems.
基金supported by grants from the Natural Science Foundation of Guangdong Province(No.06025159)the Natural Science Foundation from Department of Education of Guangdong Province(No.126(2005)).
文摘Nucleotide-binding and oligomerization domain 2(NOD2),a member of the NOD protein family,plays an important role in innate immunity.In response to pathogen attack,NOD2 stimulates cytokine and defensin production by activating nuclear factor(NF)-kB,a key transcription factor responsible for mediating downstream reactions.However,the mechanism linking NOD2 regulation and NF-kB activation is poorly understood.Using bioinformatics,we found a completely preserved canonical NF-kB binding site in the NOD2 core promoter(216 to 225 bp)in both humans and chimpanzees.The functional role of this NF-kB binding site was investigated using the enhanced green fluorescent protein(EGFP)reporter system,site-directed mutagenesis,the NF-kB activation inhibitor(JSH-23)and the chromatin immunoprecipitation(ChIP)assay.The results show that the NF-kB binding site is critical for regulation of the NOD2 gene.Either deletion of the NF-kB binding elements within the NOD2 promoter or treatment with an NF-kB activation inhibitor could lead to a significant loss of NOD2 promoter activity as detected by reporter gene assay.The canonical NF-kB binding site was bound by NF-kB as determined by the ChIP method.Based on these results,we suggest a positive feedback regulation between NF-kB and NOD2,which may represent an efficient mechanism in response to pathogen invasion.
基金supported by the Beijing-Tianjin-Hebei Basic Research Co-operation Programme S22ZX14077(Y.Z.,D.L.,and H.Z.)the National Natural Science Foundation of China(NSFC)Distinguished Young Scholar of China Program(32125002 to Y.Z.)+2 种基金the New Cornerstone foundation(Y.Z.)the Advanced Manufacturing and Engineering Programmatic Grant(A18A9b0060 to Y.W.)the Agency for Science,Technology and Research(C211917011 to Y.W.).
文摘Uric acid(UA)is a key intermediate in purine degradation across diverse organisms,while its accumulation in humans leads to inflammation and gout disease.Aerobic organisms degrade UA via a well-known“oxidative pathway”involving dearomatization of the purine core catalyzed by UA oxidases or dehydrogenases.The ability to degrade UA is also widespread in anaerobic bacteria,including gut bacteria,although the mechanisms are incompletely understood.Here,we report the biochemical characterization of a recently identified UA degradation gene cluster from Escherichia coli,and show that it encodes a“reductive pathway”for UA degradation.In this pathway,UA is first reduced to 2,8-dioxopurine(yanthine)by a xanthine dehydrogenase homolog(XdhD),followed by dearomatization of the purine core catalyzed by a flavin-dependent reductase(YgfK).Stepwise cleavage of the pyrimidine and imidazole rings forms 2,3-diureidopropionate,and stepwise cleavage of the 2-and 3-ureido groups then forms 2,3-diaminopropionate,which is cleaved by a pyridoxal 5′-phosphate-dependent lyase(YgeX)to pyruvate and ammonia.The detection of yanthine in clinical serum samples from healthy individuals and significantly higher levels from gout patients suggests that yanthine is a physiologically relevant circulating metabolite.A probiotic E.coli Nissle strain was engineered for constitutive overexpression of the gene cluster,and oral administration in a uricase-knockout hyperuricemic mouse model significantly reduced the serum UA level and alleviated associated kidney injury,suggesting a potential route towards uricolytic probiotics.
文摘The care of obstetrics patients has improved dramatically over the past few decades.Unfortunately,rates of cesarean section remain high,and decreasing this rate requires close care and follow-up in the prenatal outpatient setting.Counseling regarding cesarean delivery and vaginal delivery is imperative.Opportunities still exist in helping patients objectively weigh the decision for cesarean delivery versus vaginal delivery.Additional developments have occurred in the intrapartum and the postpartum setting,with an aim to improve patient and neonatal outcomes.Changes have been implemented for patients undergoing cesarean delivery including preoperative and intraoperative treatment of pain,nausea,and vomiting,as well as postoperative care bundles that improve patient outcomes.Innovations have also occurred in the care of postpartum patients after vaginal delivery,again with improvements in patient outcomes.This article summarizes the current evidence,provides care recommendations,and identifies the next steps in improving obstetrics care.
基金National Key Research and Development Program of China(2022YFB2803100)National Natural Science Foundation of China(62090054,62250010,62274160)+2 种基金Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021111)Strategic Leading Science and Technology Project,CAS(XDB43020100)China Computer Interconnect Technology Alliance(CCITA)Funding(20240104)。
文摘The 2μm wavelength band emerges as a promising candidate for the next communication window to enhance the transmission capacity of data.A high-responsivity and high-speed photodetector operating at 2μm is crucial for the 2-μm-wavelength-band communication system.Here,we present an on-chip waveguide-coupled germanium photodetector with remarkably high responsivity and data-receiving rate,employing subbandgap light absorption and avalanche multiplication.The device is designed with an ingenious and simple asymmetric lateral p-i-n junction structure and fabricated through a standard CMOS process by a commercial factory.It has a responsivity of 3.64 A/W and a maximum bandwidth of 50 GHz at 2μm wavelength.For the first time,to the best of our knowledge,an optical receiving rate of up to 112 Gbps is demonstrated at 2μm,verifying its feasibility in a highspeed 2-μm-band communication system.To the best of our knowledge,the proposed device stands out as the fastest photodiode with the highest responsivity among all group III-V and group IV photodetectors working in the 2μm wavelength band.
