Progressive low-density parity check (LDPC) code decoding has been widely used to correct increasing raw bit errors in NAND Flash memory. Once the decoding of a single logical page fails, the ...read-retry operation will reprocess at an increased read level with more accurate initial log-likelihood ratio (LLR) messages. However, the traditional progressive LDPC decodings with inappropriate read-level-increase granularities of read-retry operations introduce unnecessary flash read latency. By taking advantage of globally coupled LDPC (GC-LDPC) codes, an improved adaptive granularity progressive LDPC decoding (IAGPD) is proposed. This method can estimate the number of uncorrectable bit errors before each read-retry operation by detecting the unsatisfied local parity checks and general syndrome in the decoding failure. Then, it adaptively selects the optimal read-level-increase granularities for read-retry operations in the progressive LDPC decoding. Compared with the existing decoding methods, only by an extra 0.098% of the decoder area and two clock cycles, our method can reduce the flash read latency by up to 43%. And the solid-state drive (SSD) read response time on MQsim can be reduced by up to 32%.
Background
Pathogens capable of impacting gastrointestinal tract tumor development are located in the oral cavity, but whether these oral bacteria are able to colonize the gastric mucosa in gastric ...cancer (GC) patients and whether Helicobacter pylori infection can influence this process remains to be established.
Methods
Microbial 16S rDNA deep sequencing was conducted to characterize bacteria present in paired gastric mucosa and tongue coating samples in 27 patients with superficial gastritis (SG) and 11 GC patients.
Results
While the overall composition of the gastric mucosa and tongue coating microbiomes differed substantially, certain bacteria were present in both of these communities. The co‐occurrence of bacteria between the tongue coating and gastric mucosa differed significantly between SG and GC patients. Of the 15 most abundant shared oral bacteria genera (the core shared oral bacteria), which were associated with differences in microbiota composition between these tongue coating and gastric mucosa, three were enriched in the gastric mucosa of GC patients relative to SG patients, whereas, 12 were depleted in GC patient samples. Furthermore, the prevalence and relative abundance of these core shared oral bacteria in the gastric mucosa were also linked to H. pylori infection status, and the core shared oral bacteria were also associated with the overall composition of the gastric mucosal microbiome.
Conclusions
Helicobacter pylori infections are linked to the co‐occurrence of bacteria in the oral microbiome and the gastric mucosal microbiome. Ectopic colonization of oral microbes may be a primary driver of H. pylori‐induced gastric microbial dysbiosis in patients with GC.
The emergence of Y6‐type nonfullerene acceptors has greatly enhanced the power conversion efficiency (PCE) of organic solar cells (OSCs). However, which structural feature is responsible for the ...excellent photovoltaic performance is still under debate. In this study, two Y6‐like acceptors BDOTP‐1 and BDOTP‐2 were designed. Different from previous Y6‐type acceptors featuring an A–D–Aʹ–D–A structure, BDOTP‐1, and BDOTP‐2 have no electron‐deficient Aʹ fragment in the core unit. Instead, there is an electron‐rich dibenzodioxine fragment in the core. Although this modification leads to a marked change in the molecular dipole moment, electrostatic potential, frontier orbitals, and energy levels, BDOTP acceptors retain similar three‐dimensional packing capability as Y6‐type acceptors due to the similar banana‐shaped molecular configuration. BDOTP acceptors show good performance in OSCs. High PCEs of up to 18.51% (certified 17.9%) are achieved. This study suggests that the banana‐shaped configuration instead of the A–D–Aʹ–D–A structure is likely to be the determining factor in realizing high photovoltaic performance.
Acceptors BDOTP‐1 and BDOTP‐2 with an electron‐rich core fragment and three‐dimensional packing capability are developed. The excellent photovoltaic performance of Y6‐type acceptors might mainly be attributed to the banana‐shaped molecular configuration instead of the A–D–Aʹ–D–A structure.
Fullerene derivatives have been popularly applied as electron transport layers (ETLs) of inverted (p–i–n) planar heterojunction perovskite solar cells (iPSCs) due to their strong electron-accepting ...abilities, and so far, 6,6-phenyl-C61-butyric acid methyl ester (PCBM) has been the most commonly used ETL, which suffers, however, from high cost due to the complicated synthetic route. Herein, novel pyridine-functionalized fullerene derivatives (abbreviated as C60-Py) were synthesized facilely via a one-step 1,3-dipolar cycloaddition reaction and applied as ETLs superior to PCBM in iPSC devices. Three pyridine-functionalized fullerene derivatives with different alkyl groups, including methyl, n-butyl, and n-hexyl, grafted onto the pyrrolidine moiety (abbreviated as C60-MPy, C60-BPy, and C60-HPy, respectively) were synthesized. According to cyclic voltammogram study, the chain length of the N-alkyl group has negligible influence on the molecular energy level of C60-Py. However, the ETL performance of C60-Py is sensitively dependent on the chain length of the N-alkyl group, with C60-BPy exhibiting the highest power conversion efficiency (PCE) of 16.83%, which surpasses that based on PCBM ETL (15.87%). The PCE enhancement of C60-BPy device is attributed to the coordination interactions between the pyridine moiety with the Pb2+ ion of CH3NH3PbI3 perovskite, which anchor C60-BPy onto perovskite film and reinforce the passivation of the trap state within the CH3NH3PbI3 perovskite film and suppress the nonradiative electron–hole recombinations, leading to enhanced electron transport reflected by the increase of short-circuit current density (J sc). The ambient stability of C60-HPy-based device is much better than that based on PCBM ETL since its long N-alkyl group can function as a superior encapsulating layer protecting the CH3NH3PbI3 layer from contact with the ambient moisture.
Solvent-free mechanical milling is a new, environmentally friendly and cost-effective technology that is now widely used in the field of organic synthesis. The mechanochemical solvent-free synthesis ...of furoxans from aldoximes was achieved through dimerization of the in situ generated nitrile oxides in the presence of sodium chloride, Oxone and a base. A variety of furoxans was obtained with up to a 92% yield. The present protocol has the advantages of high reaction efficiency and mild reaction conditions.
Electrochemical benzylation of 60fullerene-fused lactones with different motifs unexpectedly affords three types of ring-opened benzylated adducts under different conditions. Both 60fullerene-fused ...δ- and γ-lactones can be benzylated to generate ring-opened mono- and bis-benzylated adducts in good yields. In addition, representative fullerene products have been applied as efficient electron-transport materials in perovskite solar cells.
A novel and efficient Cu(I)-catalyzed radical heteroannulation reaction of 60fullerene (C
) with α-bromo acetamides has been disclosed for the direct synthesis of diverse C
-fused lactams. ...Furthermore, the formed C
-fused lactams can be served as a versatile platform for further electrochemical functionalization to prepare 1,2-, 1,4-, 1,2,3,16-, and 1,4,9,25-adducts of C
. In addition, a representative fullerene product has been applied as an overcoating layer of the electron-transporting layer in n-type perovskite solar cell.
A direct synthesis of 2‐acylthiophenes has been developed through palladium‐catalyzed addition of thiophenes to nitriles. The reaction proceeded well under the palladium(II) acetate/2,2′‐bipyridine ...system and using D‐(+)‐camphorsulfonic acid as the additive. In addition, the obtained 2‐acylthiophenes could undergo further coupling reactions to generate novel products.
Acne vulgaris is a highly prevalent skin disorder requiring treatment and management by dermatologists. Antibiotics such as clindamycin are commonly used to treat acne vulgaris. However, from both ...medical and public health perspectives, the development of alternative remedies has become essential due to the increase in antibiotic resistance. Topical therapy is useful as a single or combined treatment for mild and moderate acne and is often employed as maintenance therapy. Thus, the current study investigated the anti-inflammatory, antibacterial, and restorative effects of sesquiterpene farnesol on acne vulgaris induced by
(
) in vitro and in a rat model. The minimum inhibitory concentration (MIC) of farnesol against
was 0.14 mM, and the IC
of 24 h exposure to farnesol in HaCaT keratinocytes was approximately 1.4 mM. Moreover, 0.8 mM farnesol exhibited the strongest effects in terms of the alleviation of inflammatory responses and abscesses and necrotic tissue repair in
-induced acne lesions; 0.4 mM farnesol and clindamycin gel also exerted similar actions after a two-time treatment. By contrast, nearly doubling the tissue repair scores, 0.4 mM farnesol displayed great anti-inflammatory and the strongest reparative actions after a four-time treatment, followed by 0.8 mM farnesol and a commercial gel. Approximately 2-10-fold decreases in interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, found by Western blot analysis, were predominantly consistent with the histopathological findings and tissue repair scores. The basal hydroxypropyl methylcellulose (HPMC) gel did not exert anti-inflammatory or reparative effects on rat acne lesions. Our results suggest that the topical application of a gel containing farnesol is a promising alternative remedy for acne vulgaris.
Imine-based covalent organic frameworks (COFs) with different functional groups have brought great application potentials in many fields, including heterogeneous catalysis. Herein, we report the ...synthesis of COFs containing carboxylic acid groups and their first application in the ruthenium-catalyzed synthesis of diarylmethane derivatives. Two new carboxyl-containing COFs (Tp-DAT and DHTA-DAT) have been prepared from 2,5-diaminoterephthalic acid and benzene-1,3,5-tricarbaldehyde derivatives with different numbers of hydroxy groups. Both Tp-DAT and DHTA-DAT COFs show high activity in the ruthenium-catalyzed
ortho
-C–H benzylation of 2-arylpyridines. Tp-DAT COF, which is fully linked by
β
-ketoenamine, has high stability, good yields and high chemoselectivity for
ortho
-benzylation and thus exhibits advantages in heterogeneous catalytic reactions.
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