Agouti-related peptide neural circuits mediate adaptive behaviors in the starved state

In the face of starvation, animals will engage in high-risk behaviors that would normally be considered maladaptive. Starving rodents, for example, will forage in areas that are more susceptible to predators and will also modulate aggressive behavior within a territory of limited or depleted nutrients. The neural basis of these adaptive behaviors likely involves circuits that link innate feeding, aggression and fear. Hypothalamic agouti-related peptide (AgRP)-expressing neurons are critically important for driving feeding and project axons to brain regions implicated in aggression and fear. Using circuit-mapping techniques in mice, we define a disynaptic network originating from a subset of AgRP neurons that project to the medial nucleus of the amygdala and then to the principal bed nucleus of the stria terminalis, which suppresses territorial aggression and reduces contextual fear. We propose that AgRP neurons serve as a master switch capable of coordinating behavioral decisions relative to internal state and environmental cues

Development of the laser decomposition process on GaN/sapphire interface layers

本論文利用雷射於元件平台區處理在不損傷電極之前提下，於元件n和p電極間之平台區域進行雷射掃描處理再搭配光輔助電化學濕式蝕刻法和化學濕式蝕刻法進行蝕刻，於藍寶石基板和GaN材料界面間產生空氣空孔和倒立的錐狀結構，成功的製備出空氣空孔和倒立的錐狀結構於圖案化GaN發光二極體元件中。本論文將探討放射狀的太陽結構下方具有空氣空孔之倒立的錐狀結構之圖案化GaN發光二極體元件(PLH-LED)和元件側壁條狀的翅膀結構下方具有空氣空孔和倒立的錐狀結構之圖案化GaN發光二極體元件(FF-LED)相較於個別傳統發光二極體(ST-LED)之光性和電性特性差異。 實驗一：PLH-LED，使用ST-LED進行試片正面雷射鑽孔處理並搭配上光輔助電化學濕式蝕刻製作出PLH-LED。而於電激發螢光(EL)量測中，PLH-LED相較於ST-LED之發光強度提升約有19 %之提升效果，是因為放射狀的太陽結構下方具有空氣空孔之倒立錐狀結構能增加光取出之區域。而於325 nm光激發螢光(PL)量測中，可明顯的觀察出在側蝕區域MQW之訊號從ST-LED之458.4 nm飄移至PLH-LED之449.9 nm，此波長之飄移方向為藍移，其是因為PLH-LED有應力釋放之效應產生，可有效降低壓電場效應，使能帶變得較為平緩。 實驗二：FF-LED，使用ST-LED進行試片正面雷射切割處理，切出切割道，接著進行試片背面雷射掃描裂解處理並搭配上化學濕式蝕刻製作出FF-LED。而於EL量測中，5 μm、10 μm、15 μm和20 μm雷射線間距之FF-LED相較於ST-LED之提升比例分別為49.42 %、62.57 %、19.58 %和11.90 %，10 μm雷射線間距之FF-LED呈現較高之發光強度提升比例，其是因為5 μm雷射線間距之FF-LED蝕刻通道較10 μm雷射線間距之FF-LED大，蝕刻後產生之倒立的錐狀結構可能已有過蝕現象，使倒立的錐狀結構產生崩塌。而於EL和PL量測中，對波長部分而言，FF-LED相較於ST-LED均有波長藍移之現象產生，其是因為製程產生之空氣空孔，造成藍寶石基板和GaN部分分離所致。於Raman光譜量測中，本實驗只挑選倒立的錐狀結構密度最高之5 μm雷射線間距之FF-LED進行量測，可明顯得知5 μm雷射線間距之FF-LED之應力值(0.29 GPa)小於ST-LED之應力值(0.99 GPa)，由此可證明FF-LED之空氣空孔和倒立的錐狀結構有助於應力之釋放。 本論文之實驗均證明了波長藍移現象是因為空氣空孔結構可使藍寶石基板和GaN部分分離，使降低GaN和基板晶格不匹配所產生之應力，可有效降低壓電場，進而使能帶變得較為平緩，所以導致波長藍移；而發光效率之提升是因為倒立的錐狀結構其傾斜角度，導致光之全反射機率增加，進而提升光取出效率，成功的探討空氣空孔和倒立的錐狀結構於圖案化發光二極體元件之貢獻和影響。利用雷射處理和光輔助電化學濕式蝕刻技術，於GaN和藍寶石基板界面間產生空氣空孔和倒立的錐狀結構，利用兩種不同製程，製作高取光效率發光二極體，應用於高效率之發光元件當中。GaN-based light-emitting diode (LED) structures had an air-void structure and a tapered GaN structure at the GaN/sapphire interface through a laser decomposition process and a wet etching process to increase light extraction efficiency. In this study, we analyzed optical and electrical of these two kinds of LEDs, a LED with a Photoelectrochemical (PEC) treated laser-drilled hole structure (PLH-LED) and a LED with a finger fork structure (FF-LED), compared to the standard LED (ST-LED). In the PLH-LED, the inverted cone-shaped GaN structure was formed around the laser-drilled hole as a light scattering structure to enhance the light extraction efficiency at central mesa region. The light output power of the PLH-LED had an approximate 19% enhancement when compared to the ST-LED at 20 mA. The photoluminescence peak wavelength of the InGaN active layer was slightly blueshifted from 458.4 nm for the ST-LED to 449.9 nm for the PLH-LED that could be caused by partially reducing the compressive strain induced piezoelectric filed by forming the radiated-cone-shaped structure at GaN/sapphire interface. High light emission intensity for the PLH-LED structure was observed around the laser-drilled hole pattern as a result of a higher light-scattering process occurring at the radiated-cone-shaped structure for the InGaN-based LED applications. In the FF-LED, the structure was fabricated through a laser scribing, laser decompose process with different line spaces and a chemical wet etching process that the InGaN active layer was not damaged in the process. The light output power of the FF-LEDs had about 49% (with 5 μm spacing), 63% (10 μm), 20% (15 μm), and 12% (20 μm) enhancement when compared to the ST-LED at 20 mA, respectively, that was caused by a partial compressed strain release at the GaN/sapphire interface by forming the tapered GaN structure. The compressed strain of the 5μm-spacing FF-LED was measued at a 0.29 GPa compared with the ST-LED (0.99 GPa) through the Raman spectra measurement that caused by forming the air void and inverted pyramid shaped structures on the roughened patterned backside at the GaN/Al2O3 interface. In the FF-LED structure, the piezoelectric field in the InGaN active layer was reduced by forming the air void structure and inverted pyramid shaped structure. The air void and inverted pyramid shaped structures at the GaN/Al2O3 interface were fabricated through these two kinds of fabrication processes on the GaN LED structures to enhance light extraction efficiency and reduce the compressive strain induced piezoelectric filed for the high efficiency GaN-based LED applications.中文摘要 i Abstract ii 章節目錄 iii 圖目錄 v 第一章 緒論 1 1-1 照明演進 1 1-2 半導體發光二極體簡介 2 1-3 Ⅲ-Ⅴ族半導體材料 2 1-4 研究動機 3 第二章 原理與文獻回顧 4 2-1 發光二極體(LED)之發光原理 4 2-2 發光二極體光取出效率 6 2-2.1 內部量子效率 7 2-2.2 外部量子效率 8 2-2.3 提升光取出效率之文獻回顧 9 2-3 壓電場(Piezoelectric field)形成 18 2-4 雷射處理 24 2-5 光輔助電化學濕式蝕刻法(PEC) 25 2-5.1 光輔助電化學氧化和蝕刻 25 2-5.2 氮化鎵(GaN)晶面蝕刻 28 第三章 實驗方法與步驟 31 3-1 實驗設計流程圖 31 3-2 試片製備流程 32 3-3 雷射處理裝置系統 42 3-4 光輔助電化學濕式蝕刻裝置 43 3-5 化學濕式蝕刻裝置 45 3-6 分析儀器 46 3-6.1光學顯微鏡(OM) 46 3-6.2 場發射掃描式電子顯微鏡(FE-SEM) 46 3-6.3 電激發螢光光譜(Electroluminescence, EL) 47 3-6.4 線掃描電激發螢光光譜(EL line scan) 48 3-6.5 光激發螢光系統(Photoluminescence, PL) 49 3-6.6 發散角量測(Radiation pattern measurement) 51 第四章 實驗結果與討論 52 4-1 放射狀的太陽結構下方具有空氣空孔之倒立的錐狀結構之圖案化GaN發光二極體元件(PLH-LED) 52 4-1.1 PLH-LED之光學顯微鏡(OM)表面形貌 52 4-1.2 PLH-LED之聚焦離子束掃描式電子顯微鏡(FIB-SEM)形貌 54 4-1.2 PLH-LED之場發掃描式電子顯微鏡(FE-SEM)形貌 56 4-1.3 PLH-LED之發光強度分布均勻性分析(beam profile) 58 4-1.4 PLH-LED操作於不同直流電下對發光強度和電性之分析 60 4-1.5 PLH-LED之光激發螢光光譜分析(Photoluminescence) 62 4-1.6 PLH-LED之變功率光激發螢光光譜分析(Power dependent PL) 64 4-2 元件側壁條狀的翅膀結構下方具有空氣空孔和倒立的錐狀結構之圖案化GaN發光二極體元件(FF-LED) 66 4-2.1 FF-LED和PLH-LED之製程差異性 66 4-2.2 FF-LED於化學濕式蝕刻之蝕刻時間定義 67 4-2.3 FF-LED之光學顯微鏡(OM)表面形貌 71 4-2.4 FF-LED之場發掃描式電子顯微鏡(FE-SEM)形貌 76 4-2.5 FF-LED之發光強度分布均勻性分析(beam profile) 79 4-2.6 FF-LED之遠場光輻射圖形特性(Far-field Radiation Patterns) 83 4-2.7 FF-LED之電激發螢光和電性量測分析 85 4-2.8 FF-LED操作於不同直流電下對波長、半高寬和外部量子效率之分析 89 4-2.9 FF-LED之電激發螢光線掃描螢光光譜分析(EL line scan) 92 4-2.10 FF-LED之光激發螢光光譜分析(Photoluminescence, PL) 97 4-2.11 FF-LED之拉曼光譜量測(Raman)分析 99 第五章 結論與未來展望 101 5-1 實驗結論 101 5-2 未來展望 102 參考文獻 10

The influence of surface electricity on internalization of Poly (amidoamine) dendrimers

Dendrimers are highly branched polymer with high density of surface functionality and core cavities. The unique architecture of dendrimers contributes to many medical application. The surface electricity of dendrimers is defined as cationic, anionic and neutral due to the functional group, amine, carboxyl and hydroxyl. The internalization of drug/gene carriers is highly interesting because it is important for designing a suitable drug/gene carrier. In this study, several endocytotic inhibitors were used to investigate the influence of surface electricity on internalization of poly (amidoamine) (PAMAM) dendrimers, and confirmed the cellular distribution of dendrimers in the presense of various endocytotic inhibitors by confocal laser scanning microscopy. The results indicate that the cellular uptakes of different PAMAM dendrimers were obviously influenced of surface functionality on the internalizations. Cationic dendrimer was shown the highest uptake by HeLa cells, while the anionic and neutral was shown rarely enter the cells. The further studies on internalization of cationic dendrimer provide a method to investigate the detail process of the attachment and further endocytosis of particle. Understanding the internalization of dendrimers may contribute to develop the modification designing for desired applications and targeting cells.1. Intruductoin……………………………………………………….………………... 1. Materials and Methods………….………………………………………………... 3.1 Chemicals and Materials…………………………………………………… 4.2 Materials for Cell Culture…………………………………………………... 5.3 Synthesis of fluorecently labeled generation 4 PAMAM-NH2 dendrimers…7.4 Synthesis of fluorecently labeled generation 4 PAMAM-OH dendrimers…. 7.5 Synthesis of fluorecently labeled generation 3.5 PAMAM-COOHendrimer…………………………………………………………………… 9.6 Cell culture…………………………………………….………………….. 10.7 Cell uptake and Inhibition studies……………………………………….... 10.8 Internalization studies………………………………………….………….. 11.9 FACS analysis……………………………………….…….……………… 12.10 Confocal laser scanning microscopy………..…………..………………… 13.11 Fluorescence microscopy studies………………………….….…………... 13. Results…………………………………………….………………………………. 15.1 Purification and fluorescence spectrum of fluorescently labeledendrimers………………………………………………………………… 15.2 Time-course cellular uptake of fluorescently labeled dendrimers………… 15.3 Effect of low temperature blocked cellular uptake……………….……….. 16.4 Influence of surface electricity and endocytotic inhibitors on cellularptake…………………………………………………………………….... 17.5 Internalization and attachment studies of dendrimer with highest uptake ofhree………………………..….…………………………….…………….. 20. Discussions………………………………………….………………………......... 23. Conclusion………………………………………………………….…………….. 33amp;#63851;考文獻…………………………………………………………….……….……….. 34錄……………………………………………………….…………………………... 4

Pricing Mortgage Insurance under Exponential L'evy Processes

[[abstract]]在美國和一些已開發的國家，房屋抵押貸款保險可以說是扮演一個很重要的角色於房屋的金融市場中，無論是在減少借貸者所暴露的風險或是助長次級的房貸市場。但事實上不明確的產權和法治效率性，甚至缺乏次級抵押市場，都被視為房屋金融市場發展水準不高的關鍵原因之一。本研究採用Bardhan, Karapandza and Urosevic(2006)之房屋抵押貸款保險訂價模型，同時主要目的在考慮房價在Levy 過程下對抵押貸款保險契約做評價。並且計算實質上房屋抵押貸款保險公司在借款者違約之下實質上的損失，可視為一個賣權的投資組合。此外本文考慮重新收回延遲的時間內的損失，求出房屋抵押貸款保險公司的公平精算現值對其評價。[[abstract]]In the United States and other developed countries mortgage insurance plays an important role in the functioning of the housing since it reduces the risk exposure of lenders and helps the creation of secondary mortgage markets But in fact in addition to unclear property rights and inefficient legal systems the absence of secondary mortgage markets has been identified as one of the key reasons for the low level of development of the housing finance market The purpose of this study is based on the model of Bardhan Karapandza and Urosevic (2006) of the pricing mortgage insurance and considers Lévy process for the housing price at the same time And this paper take into account both the fact that the realized loss for the insurer in the case of borrower’s default can be represented as a portfolio of put options In addition we consider the time of repossession procedure to price mortgage insurance contract as the actuarially fair value of the contrac

InGaN-based solar cells with a tapered GaN structure

InGaN solar cell structures had a tapered GaN structure at GaN/sapphire interface that was fabricated through a laser decomposition process and a wet crystallographic etching process. A 51% backside roughened-area ratio was observed in the treated solar cell structure to increase the light scattering process at GaN/sapphire interface. The peak external quantum efficiency (EQE) and peak wavelengths of the photovoltaic properties were measured at 38.3% (at 392 nm) and 70.5% (at 396 nm) for the conventional and the treated solar cell structures, respectively. The cutoff wavelength of the relative transmittance spectra and the wavelength of the peak EQE values for the treated solar cell structure had the redshift phenomenon which was caused by increasing light reflectance at the tapered-GaN/sapphire interface and increasing light absorption at the InGaN layers

Assessing efficacy of antiviral therapy for COVID-19 patients: A case study on remdesivir with bayesian synthesis design and multistate analysis

Background/purpose: A synthesis design and multistate analysis is required for assessing the clinical efficacy of antiviral therapy on dynamics of multistate disease progression and in reducing the mortality and enhancing the recovery of patients with COVID-19. A case study on remdesivir was illustrated for the clinical application of such a novel design and analysis. Methods: A Bayesian synthesis design was applied to integrating the empirical evidence on the one-arm compassion study and the two-arm ACTT-1 trial for COVID-19 patients treated with remdesivir. A multistate model was developed to model the dynamics of hospitalized COVID-19 patients from three transient states of low, medium-, and high-risk until the two outcomes of recovery and death. The outcome measures for clinical efficacy comprised high-risk state, death, and discharge. Results: The efficacy of remdesivir in reducing the risk of death and enhancing the odds of recovery were estimated as 31% (95% CI, 18–44%) and 10% (95% CI, 1–18%), respectively. Remdesivir therapy for patients with low-risk state showed the efficacy in reducing subsequent progression to high-risk state and death by 26% (relative rate (RR), 0.74; 95% CI, 0.55–0.93) and 62% (RR, 0.38; 95% CI, 0.29–0.48), respectively. Less but still statistically significant efficacy in mortality reduction was noted for the medium- and high-risk patients. Remdesivir treated patients had a significantly shorter period of hospitalization (9.9 days) compared with standard care group (12.9 days). Conclusion: The clinical efficacy of remdesvir therapy in reducing mortality and accelerating discharge has been proved by the Bayesian synthesis design and multistate analysis

InGaN-based Light-Emitting Diodes with a Sawtooth-shaped Sidewall on Sapphire Substrate

An InGaN light emitting diode (LED) with a cone-shaped GaN structure and a sawtooth-shaped sapphire sidewall structure was fabricated through a laser-drilling process. The fabricated procedures consisted of a laser scribing/drilling process, a wet etching process, and a chip cleaving process. In the treated LED structure with the laser-drilling sawtooth-shaped sidewall, the light output power had a 16% enhancement compared to a conventional LED structure with a laser-scribing sidewall. A periodic high light emission intensity, with a 2.6μm-width spaced at regular intervals of 3.8μm, was observed on the treated LED sidewall structure corresponding to the laser-drilling patterns. The LED structure consists of a laser-drilling sidewall and a cone-shaped GaN structure that increases the light extraction efficiency for high efficiency InGaN LED applications

An unusual case of primary hepatic lymphoma with dramatic but unsustained response to bendamustine plus rituximab and literature review

Objectives: Primary hepatic lymphoma is an uncommon cause of hepatic space-occupying lesions. Methods: We describe the case of a 73-year-old man with primary hepatic lymphoma, who presented with a low-grade fever and lower limb weakness which had progressed in the past 2 months. Results: Abdominal ultrasound and computed tomography showed multiple small hepatic tumors. Echo-guided biopsy of the hepatic tumor demonstrated primary hepatic diffuse large B cell lymphoma. Moreover, bone marrow was uninvolved, but the bone marrow smear disclosed hemophagocytosis, which is uncommon in diffuse large B cell lymphoma. Chemotherapy with bendamustine and rituximab treatment was initiated with a dramatic response: hepatic tumors markedly shrank in size shown by follow-up computed tomography and the patient returned to his normal life. Nevertheless, the response was sustained for only 8 months. Finally, the disease resisted further chemotherapy and this patient died of a severe Klebsiella pneumoniae infection. Conclusion: Chemotherapy with bendamustine and rituximab has shown a dramatic, but not durable, response in the present case with old age and multiple comorbidities