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•Aporphine alkaloids in S. epigaea were transformed into 4R-hydroxyaporphine alkaloids.•The biotransformation occurred by fermentation with C. rogersoniana.•The biotransformation was ...validated by solid- and liquid-state fermentations.•The produced alkaloids were more water soluble than the original alkaloids.•Cytochrome P450 enzymes were confirmed to participate in the catalysis.
Aporphine alkaloids were transformed into the corresponding stereospecific 4R-hydroxyaporphine alkaloids through the solid-state fermentation of Stephania epigaea with Clonostachys rogersoniana. This process was validated by both solid- and liquid-state fermentations with aporphine alkaloids as substrates. Cytochrome P450 enzymes were confirmed to participate in the catalysis of this biotransformation. 4R-Hydroxyaporphine alkaloids exhibit the same levels of acetylcholinesterase (AChE) inhibitory and cytotoxic activities as aporphine alkaloids and are considerably more water soluble than aporphine alkaloids, indicating their potential as water-soluble AChE inhibitors and antitumor agents. This paper suggests that C. rogersoniana fermentation can facilitate a novel biotransformation of aporphine alkaloids in S. epigaea to 4R-hydroxyaporphine alkaloids.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Early pregnancy loss (EPL) is a frustrating clinical problem, whose mechanisms are not completely understood. DNA methylation, which includes maintenance methylation and de novo methylation directed ...by DNA methyltransferases (DNMTs), is important for embryo development. Abnormal function of these DNMTs may have serious consequences for embryonic development.
To evaluate the possible involvement of DNA methylation in human EPL, the expression of DNMT proteins and global methylation of DNA were assessed in villous or decidua from EPL patients. The association of maintenance methylation with embryo implantation and development was also examined.
We found that DNMT1 and DNMT3A were both expressed in normal human villous and decidua. DNMT1 expression and DNA global methylation levels were significantly down-regulated in villous of EPL. DNMT3A expression was not significantly changed in the EPL group compared to controls in either villous or decidua. We also found that disturbance of maintenance methylation with a DNMT1 inhibitor may result in a decreased global DNA methylation level and impaired embryonic development in the mouse model, and inhibit in vitro embryo attachment to endometrial cells.
Our results demonstrate that defects in DNA maintenance methylation in the embryo, not in the mother, are associated with abnormal embryonic implantation and development. The findings of the current study provide new insights into the etiology of EPL.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This study reconstructed molecular networks of human immunodeficiency virus (HIV) transmission history in an area affected by an epidemic of multiple HIV-1 subtypes and assessed the efficacy of ...strengthened early antiretroviral therapy (ART) and regular interventions in preventing HIV spread. We collected demographic and clinical data of 2221 treatment-naïve HIV-1–infected patients in a long-term cohort in Shenyang, Northeast China, between 2008 and 2016. HIV pol gene sequencing was performed and molecular networks of CRF01_AE, CRF07_BC, and subtype B were inferred using HIV-TRACE with separate optimized genetic distance threshold. We identified 168 clusters containing ≥ 2 cases among CRF01_AE-, CRF07_BC-, and subtype B-infected cases, including 13 large clusters (≥ 10 cases). Individuals in large clusters were characterized by younger age, homosexual behavior, more recent infection, higher CD4 counts, and delayed/no ART (
P
< 0.001). The dynamics of large clusters were estimated by proportional detection rate (PDR), cluster growth predictor, and effective reproductive number (R
e
). Most large clusters showed decreased or stable during the study period, indicating that expansion was slowing. The proportion of newly diagnosed cases in large clusters declined from 30 to 8% between 2008 and 2016, coinciding with an increase in early ART within 6 months after diagnosis from 24 to 79%, supporting the effectiveness of strengthened early ART and continuous regular interventions. In conclusion, molecular network analyses can thus be useful for evaluating the efficacy of interventions in epidemics with a complex HIV profile.
Persistent Fault Analysis on Block Ciphers Fan Zhang; Xiaoxuan Lou; Xinjie Zhao ...
IACR transactions on cryptographic hardware and embedded systems,
08/2018, Volume:
2018, Issue:
3
Journal Article
Peer reviewed
Open access
Persistence is an intrinsic nature for many errors yet has not been caught enough attractions for years. In this paper, the feature of persistence is applied to fault attacks, and the persistent ...fault attack is proposed. Different from traditional fault attacks, adversaries can prepare the fault injection stage before the encryption stage, which relaxes the constraint of the tight-coupled time synchronization. The persistent fault analysis (PFA) is elaborated on different implementations of AES-128, specially fault hardened implementations based on Dual Modular Redundancy (DMR). Our experimental results show that PFA is quite simple and efficient in breaking these typical implementations. To show the feasibility and practicability of our attack, a case study is illustrated on the shared library Libgcrypt with rowhammer technique. Approximately 8200 ciphertexts are enough to extract the master key of AES-128 when PFA is applied to Libgcrypt1.6.3 with redundant encryption based DMR. This work puts forward a new direction of fault attacks and can be extended to attack other implementations under more interesting scenarios.
The formation of a solid electrolyte interphase on carbon anodes causes irreversible loss of Na+ ions, significantly compromising the energy density of Na-ion full cells. Sodium compensation ...additives can effectively address the irreversible sodium loss but suffer from high decomposition voltage induced by low electrochemical activity. Herein, we propose a universal electrocatalytic sodium compensation strategy by introducing a carbon nanotube (CNT)/MnO2 catalyst to realize full utilization of sodium compensation additives at a much-reduced decomposition voltage. The well-organized CNT/MnO2 composite with high catalytic activity, good electronic conductivity, and abundant reaction sites enables sodium compensation additives to decompose at significantly reduced voltages (from 4.40 to 3.90 V vs Na+/Na for sodium oxalate, 3.88 V for sodium carbonate, and even 3.80 V for sodium citrate). As a result, sodium oxalate as the optimal additive achieves a specific capacity of 394 mAh g–1, almost reaching its theoretical capacity in the first charge, increasing the energy density of the Na-ion full cell from 111 to 158 Wh kg–1 with improved cycle stability and rate capability. This work offers a valuable approach to enhance sodium compensation efficiency, promising high-performance energy storage devices in the future.
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IJS, KILJ, NUK, PNG, UL, UM
The long-term overuse of fertilizers negatively affects soil chemical properties and health, causing unsustainable agricultural development. Although many studies have focused on the effects of ...long-term fertilization on soil properties, few comparative and comprehensive studies have been conducted on fertilization management over the past 35 years in China. This meta-analysis (2058 data) evaluated the effects of the fertilizer, climate, crop types, cultivation duration and soil texture on the soil chemical properties of Chinese croplands. NPKM (NPK fertilizers + manure) led to the highest increase in pH (−0.1), soil organic carbon (SOC) (+67%), total nitrogen (TN) (+63%), alkali-hydrolysable nitrogen (AN) (+70%), total phosphorus (TP) (+149%) and available potassium (AK) (+281%) compared to the unfertilized control, while the sole nitrogen fertilizer (N) led to the lowest increase. The SOC (+115%) and TN (+84%) showed the highest increase under the influence of NPKM in an arid region. The increase in the chemical properties was higher in unflooded crops, with the maximum increase in the wheat–maize rotation, compared to rice, under NPKM. The SOC and TN increased faster under the influence of organic fertilizers (manure or straw) compared to mineral fertilization. Fertilizers produced faster effects on the change in the SOC and TN in sandy loam compared to the control. Fertilizers showed the highest and lowest effects on change in pH, organic C to total N ratio (C/N), TP and TK in clay loam with the cultivation duration. NPKM greatly increased the C/N compared to NPK in an arid region by 1.74 times and in wheat by 1.86 times. Reaching the same SOC increase, the lowest TN increase was observed in wheat, and the lowest increase in TP and AK was observed in rice, compared to the other crops. These results suggest that organic fertilizers (manure or straw) play important roles in improving soil fertility and in acidification. NPKM greatly increased the potential for soil C sequestration in wheat and in the arid region. The small increases in TP and TK can increase the SOC in rice and in the humid region. Therefore, considering the crop types and climatic conditions, reduced fertilization and the combination of mineral fertilizers with manure may be the best ways to avoid agricultural soil deterioration and increase soil carbon sequestration.
Soybean cyst nematode (SCN,
, HG) is one of the severe pests in plant-parasitic nematodes, which impairs root development and causes severe losses in soybean production worldwide. Breeding ...SCN-resistant cultivars is an important measure for securing harvests without affecting the environment, as can be done with pesticides. The majority of genetic resources for plant pest resistances are found in wild or closely related species which are often difficult to use in breeding due to crossing barriers or close linkage with unfavorable agronomic traits. In this study, 12 soybean cultivars were evaluated for their marker haplotype at the
and
SCN resistance loci and their SCN resistance tested against multiple races in environmentally controlled bioassays. The results showed that all 12 cultivars displayed Peking-type resistance marker haplotypes and all of them proved to be resistant to multiple SCN races. These cultivars provide potential for improving
resistance of soybean as donor parent in breeding and can contribute to reduce SCN field populations as part of a sustainable agriculture management.
Text summarization is an important task in natural language processing and it has been applied in many applications. Recently, abstractive summarization has attracted many attentions. However, the ...traditional evaluation metrics that consider little semantic information, are unsuitable for evaluating the quality of deep learning based abstractive summarization models, since these models may generate new words that do not exist in the original text. Moreover, the out-of-vocabulary (OOV) problem that affects the evaluation results, has not been well solved yet. To address these issues, we propose a novel model called ENMS, to enhance existing N-gram based evaluation metrics with semantics. To be specific, we present two types of methods: N-gram based Semantic Matching (NSM for short), and N-gram based Semantic Similarity (NSS for short), to improve several widely-used evaluation metrics including ROUGE (Recall-Oriented Understudy for Gisting Evaluation), BLEU (Bilingual Evaluation Understudy), etc. NSM and NSS work in different ways. The former calculates the matching degree directly, while the latter mainly improves the similarity measurement. Moreover we propose an N-gram representation mechanism to explore the vector representation of N-grams (including skip-grams). It serves as the basis of our ENMS model, in which we exploit some simple but effective integration methods to solve the OOV problem efficiently. Experimental results over the TAC AESOP dataset show that the metrics improved by our methods are well correlated with human judgements and can be used to better evaluate abstractive summarization methods.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Si-H bond activation is an important process implicated in many useful synthetic applications including silylation and transfer hydrogenation reactions. Herein we discovered homolytic activation of ...Si-H bonds on the surface of nanoporous gold (NPG), forming hydrogen radicals and Au-Si intermediates. By virtue of this new reactivity, we achieved highly selective mono and sequential alcoholysis of dihydrosilane. In addition, the amphiphilic nature of the Au-Si intermediate allows for a new bis-silylation reaction of cyclic ethers. The present work showcased that the surface reactivity of nanocatalysts may provide exciting opportunity for new reaction discovery.
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IJS, KILJ, NUK, UL, UM, UPUK
The phase cycling method is a state-of-the-art method to reconstruct complex-valued MR image. However, when it follows practical two-dimensional (2D) subsampling Cartesian acquisition which is only ...enforcing random sampling in the phase-encoding direction, a number of artifacts in magnitude appear. A modified approach is proposed to remove these artifacts under practical MRI subsampling, by adding one-dimensional total variation (TV) regularization into the phase cycling method to “pre-process” the magnitude component before its update. Furthermore, an operation used in SFISTA is employed to update the magnitude and phase images for better solutions. The results of the experiments show the ability of the proposed method to eliminate the ring artifacts and improve the magnitude reconstruction.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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