Hybrid Precoder and Combiner Design with Low Resolution Phase Shifters in mmWave MIMO Systems

Millimeter wave (mmWave) communications have been considered as a key technology for next generation cellular systems and Wi-Fi networks because of its advances in providing orders-of-magnitude wider bandwidth than current wireless networks. Economical and energy efficient analog/digial hybrid precoding and combining transceivers have been often proposed for mmWave massive multiple-input multiple-output (MIMO) systems to overcome the severe propagation loss of mmWave channels. One major shortcoming of existing solutions lies in the assumption of infinite or high-resolution phase shifters (PSs) to realize the analog beamformers. However, low-resolution PSs are typically adopted in practice to reduce the hardware cost and power consumption. Motivated by this fact, in this paper, we investigate the practical design of hybrid precoders and combiners with low-resolution PSs in mmWave MIMO systems. In particular, we propose an iterative algorithm which successively designs the low-resolution analog precoder and combiner pair for each data stream, aiming at conditionally maximizing the spectral efficiency. Then, the digital precoder and combiner are computed based on the obtained effective baseband channel to further enhance the spectral efficiency. In an effort to achieve an even more hardware-efficient large antenna array, we also investigate the design of hybrid beamformers with one-bit resolution (binary) PSs, and present a novel binary analog precoder and combiner optimization algorithm with quadratic complexity in the number of antennas. The proposed low-resolution hybrid beamforming design is further extended to multiuser MIMO communication systems. Simulation results demonstrate the performance advantages of the proposed algorithms compared to existing low-resolution hybrid beamforming designs, particularly for the one-bit resolution PS scenario

High SLFN11 expression predicts better survival for patients with KRAS exon 2 wild type colorectal cancer after treated with adjuvant oxaliplatin-based treatment

BACKGROUND: SLFN11 was reported to be a predictive marker for DNA damage drugs. The study was to investigate whether SLFN11 expression is related to sensitivity to adjuvant oxaliplatin-based treatment in colorectal cancer. METHODS: A tissue microarray, made with specimens from consecutive 261 patients who received oxaliplatin based adjuvant chemotherapy, was stained with anti-SLFN11 antibody. The staining was dichotomized as high or low expression. SLFN11 expression was correlated to clinicopathological factors, KRAS exon 2 mutation and survival. RESULTS: SLFN11 high expression was found in 16.9 % of patients, and KRAS exon 2 mutation was detected in 32.2 % of patients. SLFN11 was expressed more common in well/moderate differentiation tumors(comparing to poor differentiation ones, 21 % v 4.9 %, P = 0.003) and stage II tumors(comparing to stage III tumors, 26.1 % v 11.4 %,p = 0.006). 23 out of 153 patients with KRAS exon 2 wild-type CRC had SLFN11 high expression, no death events was recorded in the 23 patients until last follow up. These patients had significantly better overall survival (OS) than those with SLFN11 low expression tumors (100 % vs 78.2 %, log rank P = 0.048). However, among patients with KRAS exon 2 mutant tumors, OS did not significantly differ between those with SLFN11 high and SLFN11 low tumors (Log rank P = 0.709). CONCLUSIONS: SLFN11 expression predicts good better survival in colorectal cancer patients with KRAS exon 2 wild type who have received oxaliplatin based adjuvant chemotherapy

Effectiveness of multidisciplinary interventions to improve blood culture efficiency and optimize antimicrobial utilization

BackgroundThe low positive rate of blood cultures often leads to downstream consequences. We present a summary of multidisciplinary interventions implemented by a tertiary referral hospital to improve blood culture efficiency and optimize antimicrobial usage.MethodsWe evaluated the knowledge, attitude, and practice (KAP) of healthcare workers in a tertiary care hospital before and after intervention using a questionnaire. A multidisciplinary team was formed to implement the intervention, defining roles, standardizing procedures, continually improving education and feedback, and establishing incentive mechanisms. Regular quality control assessments are conducted on the responsible departments.ResultsFollowing the intervention, the median submission time for blood culture specimens was reduced from 2.2 h to 1.3 h (p < 0.001). Additionally, the intervention group showed significant (p < 0.05) increases in rates of positivity (9.9% vs. 8.6%), correct timing (98.7% vs. 89.6%), correct processing (98.1% vs. 92.3%), reduced contamination rates (0.9% vs. 1.4%), and disqualification rates (1.3% vs. 1.7%). The delivery rate of therapeutic antibacterial increased (16.1% vs. 15.2%), and the consumption of restrictive grade antimicrobial also significantly increased (26.7% vs. 22.9%). The intervention measures led to a substantial improvement in awareness and compliance with KAP of blood culture collection in the hospital. Hospital-wide antimicrobial usage deceased by 10.7% after intervention.ConclusionA multidisciplinary collaborative model proves effective in improving blood culture efficiency and optimizing antimicrobial usage

Decreased progranulin levels in patients and rats with subarachnoid hemorrhage: a potential role in inhibiting inflammation by suppressing neutrophil recruitment

BACKGROUND: Subarachnoid hemorrhage (SAH) is a devastating neurological injury with high morbidity and mortality that is mainly caused by early brain injury (EBI). Progranulin (PGRN) is known to be involved in various biological functions, such as anti-inflammation and tissue repair. This study aimed to investigate the change of PGRN in the brain after SAH and its role on EBI. METHODS: The levels of PGRN, myeloperoxidase (MPO), interleukin1β (IL-1β), and tumor necrosis factor-α (TNF-α) were detected in the cerebrospinal fluid (CSF) from SAH patients by enzyme-linked immunosorbent assay (ELISA). In addition, PGRN levels were also detected in the cerebral cortex after experimental SAH in rats by western blotting and immunohistochemistry (IHC). Recombinant human PGRN (r-PGRN) or an equal volume of phosphate-buffered saline (PBS) was administrated at 30 min after SAH. All rats were subsequently sacrificed at 24 h after SAH. Neurological score and brain water content were assessed. For mechanistic studies, the changes of MPO, matrix metalloproteinase-9 (MMP-9), zonula occludens 1 (ZO-1), Bcl-2, and cleaved caspase-3 were examined by western blotting and the levels of pro-inflammatory cytokines (IL-1β and TNF-α) were determined by ELISA. In addition, neuronal apoptosis and blood brain barrier (BBB) permeability were examined. RESULTS: The levels of PGRN significantly decreased, and the levels of MPO, IL-1β, and TNF-α were markedly elevated in the CSF from SAH patients. In rats, PGRN levels in the brain also decreased after SAH. Administration of r-PGRN decreased brain water content and improved neurological scores at 24 h after SAH. These changes were associated with marked reductions in MPO, MMP-9, and proinflammation cytokine levels, as well as increased levels of Bcl-2 and ZO-1. In addition, neuronal apoptosis and BBB permeability were alleviated by r-PGRN. CONCLUSIONS: These results indicate that the levels of PGRN decreased after SAH and that r-PGRN alleviates EBI after SAH possibly via inhibition of neutrophil recruitment, providing a new target for the treatment of SAH