പെദ് വട് ലപുഡിയിലെ കറിവേപ്പ് തോട്ടങ്ങള്‍

പെദ് വട് ലപുഡിയിലെ കറിവേപ്പ് തോട്ടങ്ങള്

Electron Mobility and Magneto Transport Study of Ultra-Thin Channel Double-Gate Si MOSFETs

We report on detailed room temperature and low temperature transport properties of double-gate Si MOSFETs with the Si well thickness in the range 7-17 nm. The devices were fabricated on silicon-on-insulator wafers utilizing wafer bonding, which enabled us to use heavily doped metallic back gate. We observe mobility enhancement effects at symmetric gate bias at room temperature, which is the finger print of the volume inversion/accumulation effect. An asymmetry in the mobility is detected at 300 K and at 1.6 K between the top and back interfaces of the Si well, which is interpreted to arise from different surface roughnesses of the interfaces. Low temperature peak mobilities of the reported devices scale monotonically with Si well thickness and the maximum low temperature mobility was 1.9 m2/Vs, which was measured from a 16.5 nm thick device. In the magneto transport data we observe single and two sub-band Landau level filling factor behavior depending on the well thickness and gate biasing

Low Temperature Properties of Quantum Antiferromagnetic Chains with Alternating Spins S=1 and 1/2

We study the low-temperature properties of S=1 and 1/2 alternating spin chains with antiferromagnetic nearest-neighbor exchange couplings using analytical techniques as well as a quantum Monte Carlo method. The spin-wave approach predicts two different low-lying excitations, which are gapped and gapless, respectively. The structure of low-lying levels is also discussed by perturbation theory in the strength of the Ising anisotropy. These analytical findings are compared with the results of quantum Monte Carlo calculations and it turns out that spin-wave theory well describes the present system. We conclude that the quantum ferrimagnetic chain exhibits both ferromagnetic and antiferromagnetic aspects.Comment: 13 pages, RevTeX, six figures, submitted to J. Phys. Cond. Ma

Current Disease Management of Primary Urethral Carcinoma

Context: Primary urethral cancer (PUC) is a rare cancer entity. Owing to the low incidence of this malignancy, the main body of literature consists mainly of case reports, making evidence-based management recommendations difficult. Objective: To review reported disease management strategies of PUC and their impact on oncological outcomes. Evidence acquisition: A systematic research was performed according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement using Medline, Scopus, and Web of Science, to find studies of the past 10yr including ≥20 patients, and investigating treatment strategies and their impact on outcomes of the three most frequent histologies: urothelial carcinoma, adenocarcinoma, and squamous cell carcinoma. Evidence synthesis: In localized PUC, penis-sparing surgery can be performed in males, while in females, complete urethrectomy with surrounding tissue is advised to minimize recurrence due to positive margins. Radiotherapy (RT) has worse survival and recurrence rates, as well as more adverse effects, than surgery, limiting its use in genital-preserving therapy. Locally advanced PUC should be treated with multimodal therapy, as monotherapies result in inferior recurrence and survival rates. Extent of surgery is still undecided, favoring radical cyst(oprostat)ectomy with total urethrectomy (RCU). Lymph node involvement is a predictor of survival, highlighting the role of lymph node dissection for disease control and staging. RT can improve survival in combination with surgery and/or chemotherapy (CHT). Neoadjuvant platinum-based CHT can improve overall and recurrence-free survival. At recurrence, salvage therapy with surgery and/or CHT can improve survival. Superficial urothelial carcinoma of the prostatic urethra can be treated with transurethral resection. Stromal invasion often features concomitant bladder cancer with a poor prognosis and requires RCU with or without systemic preoperative CHT. Conclusions: PUC is a rare malignancy with an often poor natural course, requiring a stage- and gender-specific risk-based treatment strategy. The role of systematic perioperative CHT and the extent of surgery are becoming more important. Patient summary: In this review, we looked at the treatment options for primary urethral cancer. We found that while an organ-confined disease can be managed with local resection, growth beyond the organ border makes a combination of different treatment modalities, such as surgery and systematic chemotherapy, necessary to improve outcomes