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Individual Differences in Aging: Behavioral and Neural Analyses

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Biomedical and Environmental Sciences 1991年第1期4卷 166-172页

作者： DAVID S.OLTON ALICJA MARKOWSKA STEVEN J.BRECKLER GARY L.WENK KEVIN C.PANG VASSILISKOLIATSOS Department of Psychology The Johns Hopkins University BaltimoreDepartment of Psychology The Johns Hopkins University BaltimoreDepartment of Psychology The Johns Hopkins University BaltimoreDepartment of Psychology The Johns Hopkins University BaltimoreDepartment of Psychology The Johns Hopkins University BaltimoreDepartments of Pathology and Neurology The Johns Hopkins University Baltimore Maryland 21218Maryland 21218Maryland 21218 Maryland 21218 Maryland 21218 Maryland 21205

Aged populations have remarkable variability in recent memory and cognitive mapping. Although some individuals may have substantial age-related impairments, others perform almost as well as young individuals. This paper reviews the relevant data on aged rats and indicates two challenges for biomarkers of aging. The first is to provide an appropriate quantitative description of these individual differences. The second is to use them effectively as markers for age-related changes in psychological functions and their neural substrates.

关键词： Behavioral and Neural Analyses

Recent Progress in Exploiting Small Molecule Peptides as Supramolecular Hydrogelators

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Chinese Journal of Polymer Science 2017年第10期35卷 1194-1211页

作者： Hao Su Yuzhu Wang Caleb F.Anderson Jin Mo Koo Han Wang Honggang Cui Department of Chemical and Biomolecular Engineering The Johns Hopkins University Baltimore Maryland 21218 USA Institute for NanoBio Technology The Johns Hopkins University Baltimore Maryland 21218 USA Department of Oncology and Sidney Kimmel Comprehensive Cancer Center Johns Hopkins University School of Medicine Baltimore MD 21205 USA Center for Nanomedicine The Wilmer Eye Institute Johns Hopkins University School of Medicine 400 North Broadway Baltimore MD 21231 USA

Small molecule peptides and their derivatives are an emerging class of supramolecular hydrogelators that have attracted rapidly growing interest in the fields of drug delivery and regenerative medicine due to their inherent biodegradability and biocompatibility, as well as versatility in molecular design and ease of synthesis. Built upon the directional, intermolecular interactions such as hydrogen bonding and π-π stacking, peptide-based molecular units can associate in aqueous solution into filamentous assemblies of various sizes and shapes. Under appropriate conditions, these filamentous assemblies can percolate into a 3D network with materials properties tailorable for specific biomedical applications. In this review, we survey the literature published over the past three years in the development of peptide-based hydrogelators for biomedical applications. We highlight several representative examples and center our discussion on the fundamentals of molecular design, assembly, and gelation conditions.

关键词： PNIPAM spheres reversible assembled colloidal Highly ordered assembly leaving anhydride

Electronic properties of wurtzite GaAs： A correlated structural, optical, and theoretical analysis of the same polytypic GaAs nanowire

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Nano Research 2018年第9期11卷 4708-4721页

作者： Alexander Senichev Pierre Corfdir Oliver Brandt Manfred Ramsteiner Steffen Breuer Jorg Schilling Lutz Geelhaar Peter Werner Max-Planck-lnstitut fur Mikrostrukturl)hysik Halle 06120 Germany PauI-Drude-lnstitut for Festkorperelektronik Berlin 10117 Germany Centre for Innovation Competence SiLi-nano Martin-Luther-Universitat Halle 06120 Germany present address: Birck Nanotechnology Center Purdue University West Lafayette Indiana 47907 USA present address: Fraunhofer HHI Berlin 10587 Germany present address: ABB Corporate Research Baden-Dattwi15405 Switzerland

III-V compound semiconductor nanowires are generally characterized by the coexistence of zincblende and wurtzite structures. So far, this polytypism has impeded the determination of the electronic properties of the metastable wurtzite phase of GaAs, which thus remain highly controversial. In an effort to obtain new insights into this topic, we cross-correlate nanoscale spectral imaging by near-field scanning optical microscopy with a transmission electron microscopy analysis of the very same polytypic GaAs nanowire dispersed onto a Si wafer. Thus, spatially resolved photoluminescence spectra could be unambiguously assigned to nanowire segments whose structure is known with lattice-resolved accuracy. An emission energy of 1.528 eV was observed from extended zincblende segments, revealing that the dispersed nanowire was under uniaxial strain presumably due to interaction with its supporting substrate. These crucial information and the emission energy obtained for extended pure wurtzite segments were used to perform envelope function calculations of zincblende quantum disks in a wurtzite matrix as well as the inverse structure. In these calculations, we varied the fundamental bandgap, the electron mass, and the band offset between zincblende and wurtzite GaAs. From this multi-parameter comparison with the experimental data, we deduced that the bandgap between the F8 conduction and A valence band ranges from 1.532 to 1.539 eV in strain-free wurtzite GaAs, and estimated values of 1.507 to 1.514 eV for the F7-A bandgap.

关键词： nanowires crystal-phase quantumstructures wurtzite GaAs strain near-field scanning optical microscopy photoluminescence

Sequence-Independent Identification of Active LTR Retrotransposons in Arabidopsis

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Molecular Plant 2018年第3期11卷 508-511页

作者： Jayne,Griffiths Marco,Catoni Mayumi,Iwasaki Jerzy,Paszkowski The Sainsbury Laboratory University of Cambridge Cambridge UK [∗]Corresponding author present address: university of Geneva Geneva Switzerland

Dear Editor,LTR retrotransposons （LTR-TEs） are mobile genetic elements that often comprise a large portion of the host genome and are particularly abundant in genomes of plants （Lisch, 2013）. They transpose through an RNA transcript that is reverse transcribed to an extrachromosomal DNA （ecDNA） of the original element that can insert at a new genomic location （Wicker et al., 2007）.

关键词： Arabidopsis LTR 鉴定人染色体 DNA RNA 元素植物

What India Can Learn from China and Vice Versa

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China & World Economy 2007年第3期15卷 52-69页

作者： Pieter Bottelier johns hopkins university

A partial convergence of the Indian and Chinese growth models is likely. Judging from China＇s experience, sustaining India＇s impressive economic performance of recent years will require a significant further opening of its economy （externally and internally）, higher savings and investments, especially in physical infrastructure and social services, and stronger labor absorption in the modern sectors. The base of India＇s current economic boom - software, IT-related services and high-end manufacturing - is narrow compared to China ＇s. Poor performance in agriculture is responsible for still significant poverty in many parts of rural lndia. Bilateral lndia-China ties, including trade and investment, are increasing rapidly and could help to bring about the structural economic changes India needs. Through its exports to China, lndia is becoming linked to global supply chains centered on China. The notion that India-China relations are, or are bound to become, fundamentally antagonistic, held by many in the USA, is mistaken and potentially dangerous.

关键词： comparative development economic liberalization India and China sustainable growth urban infrastructure.

Achieving Better Educational Practices Through Research Evidence:A Critical Analysis and Case Illustration of Benefits and Challenges

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ECNU Review of Education 2021年第1期4卷 108-127页

作者： Steven M.Ross Jennifer R.Morrison johns hopkins university

Purpose:We examine considerations regarding the positive contributions of evidence accountability and challenges that frustrate educators in gaining access to the needed product ***/Approach/Methods:We review the research literature on the multiple characteristics of evidence relative to consumer(practitioner)*** then examine,through a"case illustration"of an initiative in a large school district,a second challenge for evidence usage-conducting viable studies and interpreting outcomes from comprehensive interventions in complex educational ***:Despite attention being given to rigorous evidence,consumers report preferring peer recommendations and local pilot studies as *** our case illustration,we found that the availability of evidence from comprehensive formative evaluation studies was viewed by stakeholders as positively contributing to program implementation quality and sustainability over ***/Value:We use a real-world"case illustration"of a complex initiative in a large,diverse school district to illustrate how current policies and expectations regarding evidence support for educational programs is filtered through multiple agendas and personal needs of key ***,evaluators acquire nontraditional roles that go beyond routine execution of rigorous *** these factors,we offer recommendations for fostering more meaningful and objective interpretations and usage of evidence by local stakeholders.

关键词： Evidence of effectiveness program evaluation technology integration

Diagnosis and surgical management of breast cancer metastatic to the spine

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World Journal of Clinical Oncology 2014年第3期5卷 263-271页

作者： Derek G Ju Alp Yurter Ziya L Gokaslan Daniel M Sciubba Department of Neurosurgery The Johns Hopkins Medical InstitutionsJohns Hopkins University

Breast cancer is the most common malignancy and the second leading cause of death in Western women. Breast cancer most commonly metastasizes to the bone and has a particular affinity with the spine, accounting for 2/3 of osseous metastases discovered. With significant improvements in cancer therapies, the number of patients at risk for symptomatic spinal metastases is likely to increase. Patients may suffer from intractable pain and neurological dysfunction, negatively influencing their quality of life. Timely diagnosis of patients is crucial and has been aided by several breakthrough advances in imaging techniques which aid in detection, staging, and follow-up of bone metastases. Breast metastases are usually responsive to hormonal therapy and pharmacologic interventions, but skeletal metastases often require surgical intervention. The treatments are palliative but goals include the preserving or restoring neurologic function, ensuring spinal stability, and relieving pain. Advances in surgical techniques and instrumentation have allowed more effective decompres-sion and stabilization of the spine, and with the support of recent evidence the trend has shifted towards using more advanced surgical options in appropriately selected patients. In this review, the clinical presentation, diagnosis, patient selection, and surgical management of breast cancer metastatic to the spine are discussed.

关键词： Breast cancer Spine Metastasis Surgery Outcomes Decompression

Translational bioengineering strategies for peripheral nerve regeneration:opportunities,challenges,and novel concepts

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Neural Regeneration Research 2023年第6期18卷 1229-1234页

作者： Karim A.Sarhane Chenhu Qiu Thomas G.W.Harris Philip J.Hanwright Hai-Quan Mao Sami H.Tuffaha Department of Plastic and Reconstructive Surgery Peripheral Nerve Research LaboratoryJohns Hopkins University School of MedicineBaltimoreMDUSA Department of Materials Science and Engineering Johns Hopkins University Whiting School of EngineeringBaltimoreMDUSA Institute for NanoBioTechnology Johns Hopkins UniversityBaltimoreMDUSA Translational Tissue Engineering Center Johns Hopkins University School of MedicineBaltimoreMDUSA Department of Biomedical Engineering Johns Hopkins University School of MedicineBaltimoreMDUSA

Peripheral nerve injuries remain a challenging problem in need of better treatment *** best efforts at surgical reconstruction and postoperative rehabilitation,patients are often left with persistent,debilitating motor and sensory *** are currently no therapeutic strategies proven to enhance the regenerative process in humans.A clinical need exists for the development of technologies to promote nerve regeneration and improve functional *** advances in the fields of tissue engineering and nanotechnology have enabled biomaterial scaffolds to modulate the host response to tissue repair through tailored mechanical,chemical,and conductive *** bioengineered approaches have enabled targeted,sustained delivery of protein therapeutics with the capacity to unlock the clinical potential of a myriad of neurotrophic growth factors that have demonstrated promise in enhancing regenerative *** such,further exploration of combinatory strategies leveraging these technological advances may offer a pathway towards clinically translatable solutions to advance the care of patients with peripheral nerve *** review first presents the various emerging bioengineering strategies that can be applied for the management of nerve gap *** cover the rationale and limitations for their use as an alternative to autografts,focusing on the approaches to increase the number of regenerating axons crossing the repair site,and facilitating their growth towards the distal *** also discuss the emerging growth factor-based therapeutic strategies designed to improve functional outcomes in a multimodal fashion,by accelerating axonal growth,improving the distal regenerative environment,and preventing end-organs atrophy.

关键词： bioengineering biomaterials growth hormone insulin-like growth factor 1 nanotechnology neurobiology peripheral nerve regeneration Schwann cells translational research

Early detection of pancreatic cancer

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Chinese Journal of Cancer Research 2015年第4期27卷 321-331页

作者： Victoria M.Kim Nita Ahuja Department of Surgery and Medical Oncology The Sol Goldman Pancreatic Cancer Research Center The Johns Hopkins University School of Medicine Department of Urology Johns Hopkins University School of Medicine

Pancreatic adenocarcinoma is a low-incident but highly mortal disease. It accounts for only 3% of estimated new cancer cases each year but is currently the fourth common cause of cancer mortality. By 2030, it is expected to be the 2nd leading cause of cancer death. There is a clear need to diagnose and classify pancreatic cancer at earlier stages in order to give patients the best chance at a definitive cure through surgery. Three precursor lesions that distinctly lead to pancreatic adenocarcinoma have been identified, and we have increasing understanding the non-genetic and genetic risk factors for the disease. With increased understanding about the risk factors, the familial patters, and associated accumulation of genetic mutations involved in pancreatic cancer, we know that there are mutations that occur early in the development of pancreatic cancer and that improved genetic risk-based strategies in screening for pancreatic cancer may be possible and successful at saving or prolonging lives. The remaining challenge is that current standards for diagnosing pancreatic cancer remain too invasive and too costly for widespread screening for pancreatic cancer. Furthermore, the promises of noninvasive methods of detection such as blood, saliva, and stool remain underdeveloped or lack robust testing. However, significant progress has been made, and we are drawing closer to a strategy for the screening and early detection of pancreatic cancer.

关键词： Early detection screening pancreatic cancer familial pancreatic cancer