Iterative decoding for magnetic recording channels.

The success of turbo codes indicates that performance close to the Shannon limit may be achieved by iterative decoding. This has in turn stimulated interest in the performance of iterative detection for partial-response channels, which has been an active research area since 1999. In this dissertation, the performance of serially concatenated recording systems is investigated by computer simulations as well as experimentally. The experimental results show that the iterative detection algorithm is not sensitive to channel nonlinearities and the turbo coded partial-response channel is substantially better than partial-response maximum-likelihood channels. The classical iterative decoding algorithm was originally designed for additive white Gaussian noise channels. This dissertation shows that the performance of iterative detection can be significantly improved by considering the noise correlation of the magnetic recording channel. The idea is to iteratively estimate the correlated noise sequence at each iteration. To take advantage of the noise estimate, two prediction techniques were proposed, and the corresponding systems were named noise predictive turbo systems. These noise predictive turbo systems can be generalized to other detector architectures for magnetic recording channels straightforwardly

Quantum Interference of Hydrodynamic Modes in a Dirty Marginal Fermi Liquid

We study the electrical transport of a two-dimensional non-Fermi liquid with disorder, and we determine the first quantum correction to the semiclassical dc conductivity due to quantum interference. We consider a system with $N$ flavors of fermions coupled to SU($N$) critical matrix bosons. Motivated by the SYK model, we employ the bilocal field formalism and derive a set of finite-temperature saddle-point equations governing the fermionic and bosonic self-energies in the large-$N$ limit. Interestingly, disorder smearing induces a marginal Fermi liquid (MFL) self-energy for the fermions. We next consider fluctuations around the saddle points and derive a MFL-Finkel'stein nonlinear sigma model. We find that the Altshuler-Aronov quantum conductance correction gives linear-$T$ resistivity that can dominate over the Drude result at low temperature. The strong temperature dependence of the quantum correction arises due to rapid relaxation of the mediating quantum-critical bosons. We verify that our calculations explicitly satisfy the Ward identity at the semiclassical and quantum levels. Our results establish that quantum interference persists in two-particle hydrodynamic modes, even when quasiparticles are subject to strong (Planckian) dissipation.Comment: v2: corrected semiclassical conductivity; 39 pages, 19 figures; v3: published versio

Malignant melanoma of the penis and urethra: one case report

We present a case of a patient with malignant melanoma of the glans penis and urethra, which was found in a 53-year-old man with nonhealing ulcerative penile lesion and bilateral, clinically palpable inguinal lymphadenopathies at diagnosis. A diagnostic biopsy showed the characteristics of a melanoma. We treated the patient with total penectomy and bilateral inguinal lymph node dissection. After surgery, chemotherapy with bleomycin, vincristine and cisplatin and immunotherapy with thymosin injection were started. No recurrence or metastasis occurred during the 3 years after the operation. Melanoma of the penis is very rare, and early diagnosis is important because the patient prognosis is very poor

FDNet: Feature Decoupled Segmentation Network for Tooth CBCT Image

Precise Tooth Cone Beam Computed Tomography (CBCT) image segmentation is crucial for orthodontic treatment planning. In this paper, we propose FDNet, a Feature Decoupled Segmentation Network, to excel in the face of the variable dental conditions encountered in CBCT scans, such as complex artifacts and indistinct tooth boundaries. The Low-Frequency Wavelet Transform (LF-Wavelet) is employed to enrich the semantic content by emphasizing the global structural integrity of the teeth, while the SAM encoder is leveraged to refine the boundary delineation, thus improving the contrast between adjacent dental structures. By integrating these dual aspects, FDNet adeptly addresses the semantic gap, providing a detailed and accurate segmentation. The framework's effectiveness is validated through rigorous benchmarks, achieving the top Dice and IoU scores of 85.28% and 75.23%, respectively. This innovative decoupling of semantic and boundary features capitalizes on the unique strengths of each element to significantly elevate the quality of segmentation performance.Comment: This work has been submitted to the IEEE ISBI 2024 for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Pathologic complete response of hepatoid adenocarcinoma of the stomach after chemo-immunotherapy: A rare case report and literature review

BackgroundHepatoid adenocarcinoma of the stomach (HAS) is a highly malignant subtype of gastric carcinoma with specific clinicopathological features and extremely poor prognosis. We present an exceedingly rare case of complete response after chemo-immunotherapy.Case DescriptionA 48-year-old woman with highly elevated serum alpha-fetoprotein (AFP) level was found to have HAS verified by pathological examination based on gastroscopy. Computed tomography scan was done and TNM staging of the tumor was T4aN3aMx. Programmed cell death ligand-1 (PD-L1) immunohistochemistry was performed, revealing a negative PD-L1 expression. Chemo-immunotherapy including oxaliplatin plus S-1 and PD-1 inhibitor terelizumab was given to this patient for 2 months until the serum AFP level decreased from 748.5 to 12.9 ng/mL and the tumor shrank. D2 radical gastrectomy was then performed and histopathology of the resected specimen revealed that the cancerous cells had disappeared. Pathologic complete response (pCR) was achieved and no evidence of recurrence has been found after 1 year of follow-up.ConclusionsWe, for the first time, reported an HAS patient with negative PD-L1 expression who achieved pCR from the combined chemotherapy and immunotherapy. Although no consensus has been reached regarding the therapy, it might provide a potential effective management strategy for HAS patient

Microrna Expression Profile and Differentially-Expressed Genes in Prolactinomas Following Bromocriptine Treatment

Little is known about the function of microRNAs in prolactinomas treated with bromocriptine. The aim of the study was to explore the microRNAs associated with bromocriptine-treated prolactinomas. Six prolactinoma samples were selected according to whether they received bromocriptine treatment or not before microsurgery, and microRNA expression profiles of bromocriptine-treated and untreated prolactinomas were screened by the miRCURY LNA Array. The differentially expressed microRNAs in microarrays were further validated by stem-loop real-time PCR and subjected to gene ontology analysis and KEGG pathway analysis. In addition, related genes of microRNAs were analyzed by qRT-PCR in 15 prolactinoma samples. The initial analysis by microarrays generated a list of 80 upregulated microRNAs and 71 downregulated microRNAs in treated prolactinomas compared to untreated prolactinomas. miR-206, miR-516b and miR-550 were confirmed to be significantly upregulated, while miR-671-5p was confirmed to be significantly downregulated in treated prolactinomas by qRT-PCR. microRNA-mRNA network analysis integrating GO and KEGG pathway annotation displayed some critical factors. Platelet-derived growth factor α polypeptide (PDGFA) and bone morphogenetic protein 4 (BMP4), were verified to be differentially expressed between the two groups. PDGFA was significantly upregulated in treated prolactinomas, while BMP4 was significantly downregulated in treated prolactinomas. Our study reveals differential expression of microRNAs in prolactinoma after pharmacotherapy. Specific microRNAs may be involved in the inhibition or promotion of prolactinoma tumor growth impacted by bromocriptine pharmacotherapy. PDGFA and BMP4 may be involved in the pharmacotherapy mechanism of prolactinoma