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Zinc-oxide/PDMS-clad tapered fiber saturable absorber for passively mode-locked erbium-doped fiber laser

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Chinese Physics B 2021年第5期30卷 384-389页

作者： F D Muhammad S A S Husin E k Ng k y lau C A C Abdullah M A Mahdi Department of Physics Faculty of ScienceUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Wireless and Photonics Networks Research Centre Faculty of EngineeringUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Department of Electronics and Nanoengineering Tietotie 3Aalto University02150 EspooFinland

We propose and demonstrate a passively mode-locked erbium-doped fiber laser(EDFL)based on zinc-oxide/polydimethylsiloxane(ZnO/PDMS)saturable absorber(SA)that evanescently interacts with the light on a tapered *** ZnO/PDMS composite is coated on the whole surface of the tapered fiber to guarantee the maximum efficiency of the SA device,with a measured insertion loss of 0.87 dB and a modulation depth of 6.4%.The proposed laser can generate soliton mode-locking operation at a threshold power of 33.07 *** generated output pulse yields a repetition rate and pulse width of 9.77 MHz and 1.03 ps,*** results indicate that the proposed ZnO/PDMS-clad tapered fiber could be useful as an efficient,compatible,and low-cost SA device for ultrafast laser applications.

关键词： zinc-oxide saturable absorber tapered fiber mode-locked fiber laser

Stigmatic exudate in the Annonaceae:Pollinator reward,pollen germination medium or extragynoecial compitum?

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Journal of Integrative Plant Biology 2017年第12期59卷 881-894页

作者： Jenny y.y.lau Chun-Chiu Pang Lawrence Ramsden Richard M.k.Saunders School of Biological Sciences the University of Hong KongPokfulam RoadHong KongChina

Although ＂dry-type＂ stigmas are widely re- garded as ancestral in angiosperms, the early-divergent family Annonaceae has copious stigmatic exudate. We evaluate three putative functions for this exudate： as a nutritive reward for pollinators; as a pollen germination medium; and as an extragynoecial compitum that enables pollen tube growth between carpels. Stigmatic exudate is fructose dominated （72.2%）, but with high levels of glucose and sucrose; the dominance of hexose sugars and the diversity of amino acids observed, including many that are essential for insects, support a nutritive role for pollinators. Sugar concentration in pre-receptive flowers is high （28.2%）, falling during the peak period of stigmatic receptivity （17.4%）, and then rising again toward the end of the pistillate phase （32.9%）. Pollen germination was highest in sugar concentrations 〈2%. Sugar concentrations during the peak pistillate phase therefore provide optimal osmolarity for pollen hydration and germination; subsequent changes in sugar concentration during anthesis reinforce protogyny （in which carpels mature before stamens）, enabling the retention of concentrated exudate into the staminate phase as a pollinator food reward without the possibility of pollen germination. Intercarpellary growth of pollen tubes was confirmed： the exudate therefore also functions as a suprastylar extragynoecial compitum, overcoming the limitations of apocarpy.

关键词： Stigmatic exudate in the Annonaceae pollen germination medium or extragynoecial compitum Pollinator reward

Romance of the three domains:how cladistics transformed the classifi cation of cellular organisms

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Protein & Cell 2013年第9期4卷 664-676页

作者： Chi-Chun Ho Susanna k.P.lau Patrick C.y.Woo Department of Microbiology The University of Hong KongHong KongChina State key Laboratory of Emerging Infectious Diseases The University of Hong KongHong KongChina Research Centre of Infection and Immunology The University of Hong KongHong KongChina Carol yu Centre of Infection The University of Hong KongHong KongChina

Cladistics is a biological philosophy that uses genealogi-cal relationship among species and an inferred sequence of divergence as the basis of classifi *** review critically surveys the chronological development of bio-logical classification from Aristotle through our post-genomic era with a central focus on *** 1957,Julian Huxley coined cladogenesis to denote splitting from *** 1960,the English translation of Willi Hennig’s 1950 work,Systematic Phylogenetics,was published,which received strong opposition from phenet-icists,such as numerical taxonomists Peter Sneath and Robert Sokal,and evolutionary taxonomist,Ernst Mayr,and sparked acrimonious debates in *** 1977-1990,Carl Woese pioneered in using small subunit rRNA gene sequences to delimitate the three domains of cellu-lar life and established major prokaryotic *** has since dominated *** being compatible with modern microbiological observations,*** with unusual phenotypes,restricted expression of charac-teristics and occasionally being uncultivable,increasing recognition of pervasiveness and abundance of horizon-tal gene transfer has challenged relevance and validity of *** mosaic nature of eukaryotic and prokary-otic genomes was also gradually *** the mid-2000s,high-throughput and whole-genome sequencing became routine and complex geneologies of organisms have led to the proposal of a reticulated web of *** genomics only indirectly leads to understanding of func-tional adaptations to ecological niches,computational modeling of entire organisms is underway and the gap between genomics and phenetics may soon be *** are not expected to settle as taxonomic classifi cations shall remain subjective to serve the human scientist,not the classifi ed.

关键词： cladistics phenetics phylogeny classifi ca-tion evolution

The Aerosol-Monsoon Climate System of Asia:A New Paradigm

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Journal of Meteorological Research 2016年第1期30卷 1-11页

作者： William k.M.lau Earth Science Interdisciplinary Center University of MarylandCollege Park

This commentary is based on a series of recent lectures on aerosol-monsoon interactions I gave at the Beijing Normal University in August 2015. A main theme of the lectures is on a new paradigm of ＂An Aerosol-Monsoon-Climate-System＂, which posits that aerosol, like rainfall, cloud, and wind, is an integral component of the monsoon climate system, influencing monsoon weather and climate on M1 timescales. Here, salient issues discussed in my lectures and my personal perspective regarding interactions between atmospheric dynamics and aerosols from both natural and anthropogenic sources are summarized. My hope is that under this new paradigm, we can break down traditional disciplinary barriers, advance a deeper understanding of weather and climate in monsoon regions, as well as entrain a new generation of geoscientists to strive for a sustainable future for one of the most complex and challenging human-natural climate sub-system of the earth.

关键词： aerosol monsoon climate system interaction new paradigm

Evolving treatment landscape for early and advanced pancreatic cancer

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World Journal of Gastrointestinal Oncology 2017年第7期9卷 281-292页

作者： Sally C lau Winson y Cheung Division of Medical Oncology University of British Columbia British Columbia Cancer Agency Department of Oncology University of Calgary Tom Baker Cancer Center

Pancreatic ductal adenocarcinoma is an infrequent cancer with a high disease related mortality rate, even in the context of early stage disease. Until recently, the rate of death from pancreatic cancer has remained largely similar whereby gemcitabine monotherapy was the mainstay of systemic treatment for most stages of disease. With the discovery of active multiagent chemotherapy regimens, namely FOLFIRINOX and gemcitabine plus nab-paclitaxel, the treatment landscape of pancreatic cancer is slowly evolving. FOLFIRINOX and gemcitabine plus nab-paclitaxel are now considered standard first line treatment options in metastatic pancreatic cancer. Studies are ongoing to investigate the utility of these same regimens in the adjuvant setting. The potential of these treatments to downstage disease is also being actively examined in the locally advanced context since neoadjuvant approaches may improve resection rates and surgical outcomes. As more emerging data become available, the management of pancreatic cancer is anticipated to change significantly in the coming years.

关键词： Cancer Neoplasm Pancreas Adjuvant treatment Systemic treatment Gemcitabine FOLFIRINOX Nab-paclitaxel

Methods of vascular control technique during liver resection:a comprehensive review

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Hepatobiliary & Pancreatic Diseases International 2010年第5期9卷 473-481页

作者： Wan-yee lau Eric C.H.Lai Stephanie H.y.lau Faculty of Medicine the Chinese University of Hong KongShatinNew TerritoriesHong Kong SARChina

BACkGROUND: Significant hemorrhage together with blood transfusion increases postoperative morbidity and mortality of hepatic resection. Hepatic vascular occlusion is effective in minimizing bleeding during hepatic parenchymal transection. This article aimed to review the current role and status of various techniques of hepatic vascular occlusion during hepatic resection. DATA SOURCES: The relevant manuscripts were identified by searching MEDLINE, and PubMed for articles published between January 1980 and April 2010 using the keywords 'vascular control', 'vascular clamping', 'vascular exclusion' and 'hepatectomy'. Additional papers were identified by a manual search of the references from the key articles. RESULTS: One randomized controlled trial (RCT) and 5 RCTs showed intermittent Pringle maneuver and ischemic preconditioning followed by continuous Pringle maneuver were superior to continuous Pringle maneuver alone, respectively. Two RCTs compared the outcomes of hepatectomy with and without intermittent Pringle maneuver. One showed Pringle maneuver to be beneficial, while the other failed to show any benefit. One RCT showed that ischemic preconditioning had significantly less blood loss than using intermittent Pringle maneuver. Four RCTs evaluated the use of hemihepatic vascular occlusion. One RCT showed it had significantly less blood loss than Pringle maneuver, while the other 3 showed no significant difference. Only 1 RCT showed it had significantly less liver ischemic injury. No RCT had been carried out to assess segmental vascular occlusion. Two RCTs compared the outcomes of total hepatic vascular exclusion (THVE) and Pringle maneuver. One RCT showed THVE resulted in similar blood loss, but a higher postoperative complication. The other RCT showed less blood loss using THVE but the postoperative complication rate was similar. Both studies showed similar degree of liver ischemic injury. Only one RCT showed that selective hepatic vascular exclusion (SHVE) had

关键词： vascular control vascular exclusion hepatectomy liver neoplasm Pringle maneuver

The current role of neoadjuvant/adjuvant/chemoprevention therapy in partial hepatectomy for hepatocellular carcinoma:a systematic review

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Hepatobiliary & Pancreatic Diseases International 2009年第2期8卷 124-133页

作者： Wan-yee lau Eric C.H.Lai Stephanie H.y.lau State key Laboratory for Diagnosis and Treatment of Infectious Diseases First Affiliated HospitalZhejiang University School of Medicine

BACkGROUND: Following curative treatment for hepatocellular carcinoma (HCC), 50%-90% of postoperative death is due to recurrent disease. Intra-hepatic recurrence is frequently the only site of recurrence. Thus, any neoadjuvant or adjuvant therapy, which can decrease or delay the incidence of intra-hepatic recurrence, or any cancer chemoprevention which can prevent a new HCC from developing in the liver remnant, will improve the results of liver resection. This article systematically reviewed the current evidence of neoadjuvant, adjuvant, and chemoprevention in partial hepatectomy of HCC. DATA SOURCES: Studies were identified by searching MEDLINE and PubMed databases for articles from January 1990 to November 2008 using the keywords 'hepatocellular carcinoma', 'hepatectomy', 'adjuvant therapy', 'neoadjuvant therapy', and 'regional therapy'. Additional papers and book chapters were identified by a manual search of the references from the key articles. RESULTS: Neoadjuvant transarterial chemoembolization or adjuvant regional transarterial chemotherapy embolization+systemic chemotherapy did not add benefit. Both adjuvant transarterial radioembolization with (131)I-lipiodol and adjuvant systemic interferon showed promising results. However, there were only a limited number of such studies. CONCLUSIONS: Further randomized controlled studies need to be carried out. Currently, there is no consensus on a standard neoadjuvant/adjuvant/chemoprevention therapy in partial hepatectomy for HCC.

关键词： hepatocellular carcinoma hepatectomy adjuvant therapy neoadjuvant therapy therapeutic embolization

Accurate ab initio Predictions of Ionization Energies and Heats of Formation for Cyclopropenylidene, Propargylene and Propadienylidene

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Chinese Journal of Chemical Physics 2006年第1期19卷 29-38页

作者： k. C. lau C. y. Ng James Franck Institute and Department of Chemistry University of Chicago Chicago 60637 USA Department of Chemistry University of California Davis One Shields Avenue Davis California95616 USA

The ionization energies （IEs） of cyclopropenylidene （c-C3H2）, propargylene （HCCCH） and propadienylidene （H2CCC） have been computed using the CCSD（T）/CBS method, which involves the approxixnation to the complete basis set （CBS） limit at the coupled cluster level with single and double excitations plus quasi-perturbative triple excitation effect （CCSD（T））. The zero-point vibrational energy correction, the core-valence electronic correction, the scalar relativistic effect and the high level correction beyond the CCSD（T） excitations have also been made in these calculations. The CCSD（T）/CBS values for the IN（c-C3H2） and IE（HCCCH） of 9.164, 8.987 eV are in good agreement with the experimental values of （9.15±0.03） and （8.96±0.04） eV. The CCSD（T）/CBS calculations yield the IE values of 10.477 and 10.388 eV for the ionization transitions H2CCC→H2CCC^＋（^2A1, C2v） and H2CCC→H2CCC＋（^2A＇, Cs）, respectively. On the basis of the Franek-Condon factor consideration, the IE of （10.43±0.02） eV determined in the previous single-photon ionization experiment most likely corresponds to the ionization threshold for the H2CCC→H2CCC^＋（^2A1, C2v） transition. Although the precision of the experimental IN measurements fpr c-C3H2, HCCCH, and H2CCC is insufficient to pin down the accuracy of the theoretical calculations to better than ±30 meV, the excellent agreement between the experimental and theoretical IE values observed in the present study indicates that the CCSD（T）/CBS calculations together with high-order correlation corrections are capable of yielding reliable IE predictions for simple hydrocarbon carbenes and bi-radicals. We have also reported the heats of formation at 0 k （△H^of0） and 298 k （△H^of298）for c-C3H2/c-C3H2^＋, HCCCH/HCCCH^＋, and H2CCC/H2CCC^＋, The available experimental △H^of0 and △H^of298 values for c-C3H2/c C3H2^＋, HCCCH/HCCCH^＋ are found to be in good accord with the CCSD（T）/CBS predictions after taking into account the experimental uncertainties.

关键词： Ab intio Ionization energy Heat of formation c-C3H2 HCCCH H2CCC

Chromatic Uniqueness of Certain Complete Tripartite Graphs

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Acta Mathematica Sinica,English Series 2011年第5期27卷 919-926页

作者： G. C. lau y. H. PENG Faculty of Computer & Mathematical Sciences Universiti Teknologi MARA (Segamat Campus) 85100 Segamat Johor Malaysia Department of Mathematics and Institute for Mathematical Research Universiti Putra Malaysia 43400 UPM Serdang Malaysia

Let P（G,A） be the chromatic polynomial of a graph G. A graph G is chromatically unique if for any graph H, P（H, λ） = P（G, λ） implies H is isomorphic to G. Liu et al. [Liu, R. y., Zhao, H. X., ye, C. F.： A complete solution to a conjecture on chromatic uniqueness of complete tripartite graphs. Discrete Math., 289, 175 179 （2004）], and lau and Peng [lau, G. C., Peng, y. H.： Chromatic uniqueness of certain complete t-partite graphs. Ars Comb., 92, 353-376 （2009）] show that k（p - k,p - i,p） for i = 0, 1 are chromatically unique if p ≥ k ＋ 2 ≥ 4. In this paper, we show that if 2 〈 i 〈 4, the complete tripartite graph k（p - k,p - i,p） is chromatically unique for integers k ≥ i and p 〉 k2/4 ＋ i ＋ 1.

关键词： Complete tripartit graphs chromatic polynomial chromatic uniqueness