143 research outputs found

    A Unifying Quantum Speed Limit For Time-Independent Hamiltonian Evolution

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    Quantum speed limit (QSL) is the study of fundamental limits on the evolution time of quantum systems. For instance, under the action of a time-independent Hamiltonian, the evolution time between an initial and a final quantum state obeys various mutually complementary lower bounds. They include the Mandelstam-Tamm bound, the Margolus-Levitin bound, the Luo-Zhang bound and the Lee-Chau bound. Here we show that the Mandelstam-Tamm bound can be obtained by optimizing the Lee-Chau bound over a certain parameter. More importantly, we report a QSL that includes all the above bounds as special cases before optimizing over the physically meaningless reference energy level of a quantum system. This unifying bound depends on a certain parameter pp. For any fixed pp, we find all pairs of time-independent Hamiltonian and initial pure quantum state that saturate this unifying bound. More importantly, these pairs allow us to compute this bound accurately and efficiently using an oracle that returns certain ppth moments related to the absolute value of energy of the quantum state. Moreover, this oracle can be simulated by a computationally efficient and accurate algorithm for finite-dimensional quantum systems as well as for certain infinite-dimensional quantum states with bounded and continuous energy spectra. We further compare the performance of this bound for the case of a fixed pp as well as the case of optimizing over pp with existing QSLs. We find that if the dimension of the underlying Hilbert space is 2000\lesssim 2000, our unifying bound optimized over pp can be computed accurately in a few minutes using Mathematica code with just-in-time compilation in a typical desktop. Besides, this optimized unifying QSL is at least as good as all the existing ones combined and can occasionally be a few percent to a few times better.Comment: 20 pages, 3 figure

    A Scorpion Defensin BmKDfsin4 Inhibits Hepatitis B Virus Replication in Vitro

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    Hepatitis B virus (HBV) infection is a major worldwide health problem which can cause acute and chronic hepatitis and can significantly increase the risk of liver cirrhosis and primary hepatocellular carcinoma (HCC). Nowadays, clinical therapies of HBV infection still mainly rely on nucleotide analogs and interferons, the usage of which is limited by drug-resistant mutation or side effects. Defensins had been reported to effectively inhibit the proliferation of bacteria, fungi, parasites and viruses. Here, we screened the anti-HBV activity of 25 scorpion-derived peptides most recently characterized by our group. Through evaluating anti-HBV activity and cytotoxicity, we found that BmKDfsin4, a scorpion defensin with antibacterial and Kv1.3-blocking activities, has a comparable high inhibitory rate of both HBeAg and HBsAg in HepG2.2.15 culture medium and low cytotoxicity to HepG2.2.15. Then, our experimental results further showed that BmKDfsin4 can dose-dependently decrease the production of HBV DNA and HBV viral proteins in both culture medium and cell lysate. Interestingly, BmKDfsin4 exerted high serum stability. Together, this study indicates that the scorpion defensin BmKDfsin4 also has inhibitory activity against HBV replication along with its antibacterial and potassium ion channel Kv1.3-blocking activities, which shows that BmKDfsin4 is a uniquely multifunctional defensin molecule. Our work also provides a good molecule material which will be used to investigate the link or relationship of its antiviral, antibacterial and ion channel–modulating activities in the future

    Highly Branched Poly(5-amino-1-pentanol-co-1,4- butanediol diacrylate) for High Performance Gene Transfection

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    The top-performing linear poly(β-amino ester) (LPAE), poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) (C32), has demonstrated gene transfection efficiency comparable to viral-mediated gene delivery. Herein, we report the synthesis of a series of highly branched poly(5-amino-1-pentanol-co-1,4-butanediol diacrylate) (HC32) and explore how the branching structure influences the performance of C32 in gene transfection. HC32 were synthesized by an “A2 + B3 + C2” Michal addition strategy. Gaussia luciferase (Gluciferase) and green fluorescent protein (GFP) coding plasmid DNA were used as reporter genes and the gene transfection efficiency was evaluated in human cervical cancer cell line (HeLa) and human recessive dystrophic epidermolysis bullosa keratinocyte (RDEBK) cells. We found that the optimal branching structure led to a much higher gene transfection efficiency in comparison to its linear counterpart and commercial reagents, while preserving high cell viability in both cell types. The branching strategy affected DNA binding, proton buffering capacity and degradation of polymers as well as size, zeta potential, stability, and DNA release rate of polyplexes significantly. Polymer degradation and DNA release rate played pivotal parts in achieving the high gene transfection efficiency of HC32-103 polymers, providing new insights for the development of poly(β-amino ester)s-based gene delivery vectors

    Cell origin of endometriosis: contribution by the fallopian tube epithelium

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    Abstract: Endometriosis is one of the most enigmatic diseases in women. Extensive research has been carried out in the past since endometriosis has a significant impact in women's life. However, the pathogenesis of endometriosis remains unclear. In this review, we briefly summarized four main theories associated with the cell origin of endometriosis including retrograde menstruation, coelomic metaplasia from ovarian or peritoneal surface, embryonic rests from Müllerian tissue, and endometrioid tissue induction by hematopoietic stem cells. In addition, we have added our recently proposed theory of tubal origin of ovarian endometriosis based on our clinicopathological observations and recent experimental results. It would be interesting to know if the tubal contribution in the genesis of ovarian endometriosis can be truly accepted in future after additional in depth studies in various clinical, pathological, and molecular levels

    Versatile Hyperbranched Poly(β-Hydrazide Ester) Macromers as Injectable Antioxidative Hydrogels

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    Synthetic reactive oxygen species (ROS)-responsive biomaterials have emerged as a useful platform for regulating critical aspects of ROS-induced pathologies and can improve such hostile microenvironments. Here, we report a series of new hyperbranched poly­(β-hydrazide ester) macromers (HB-PBHEs) with disulfide moieties synthesized via an “A2 + B4” Michael addition approach. The three-dimensional structure of HB-PBHEs with multiacrylate end groups endows the macromers with rapid gelation capabilities to form (1) injectable hydrogels via cross-linking with thiolated hyaluronic acid and (2) robust UV-cross-linked hydrogels. The disulfide-containing macromers and hydrogels exhibit H2O2-responsive degradation compared with the counterparts synthesized by a dihydrazide monomer without disulfide moieties. The cell viability under a high ROS environment can be well-maintained under the protection of the disulfide containing hydrogels

    Enhanced Gene Transfection Efficacy and Safety Through Granular Hydrogel Mediated Gene Delivery Process

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    Although gene therapy has made great achievements in both laboratory research and clinical translation, there are still challenges such as limited control of drug pharmacokinetics, acute toxicity, poor tissue retention, insufficient efficacy, and inconsistent clinical translation. Herein, a gene therapy gel is formulated by directly redispersing polyplex nanoparticles into granular hydrogels without any gelation pre-treatment, which provides great convenience for storage, dosing and administration. In vitro studies have shown that use of granular hydrogels can regulate the gene drug release, reduce dose dependent toxicity and help improve transfection efficacy. Moreover, the developed gene therapy gel is easy to operate and can be directly used in vitro to evaluate its synergistic efficacy with various gene delivery systems. As such, it represents a major advance over many conventional excipient-based formulations, and new regulatory strategies for gene therapy may be inspired by it

    Predicting treatment failure in stage III colon cancer patients after radical surgery

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    PurposeThe aim to assess treatment failure in patients with stage III colon cancer who underwent radical surgery and was analyzed using the nomogram.MethodsClinical factors and survival outcomes for stage III colon cancer patients registered in the SEER database from 2018 to 2019 were analyzed, with patients split into training and testing cohorts (7:3 ratio). A total of 360 patients from the First Affiliated Hospital of Longyan served as an external validation cohort. Independent predictors of treatment failure were identified using logistic regression analyses. The nomograms was evaluated by concordance index (C-index), calibration curves, and the area under the curve (AUC), decision curve analysis (DCA) and clinical impact curves (CIC) assessed the clinical utility of nomograms versus TNM staging.ResultsThe study included 4,115 patients with stage III colon cancer. Multivariate logistic analysis age, tumor site, pT stage, pN stage, chemotherapy, pretreatment CEA levels, number of harvested lymph nodes, perineural invasion and marital status were identified as independent risk factors for treatment failure. The C-indices for the training and testing sets were 0.853 and 0.841. Validation by ROC and calibration curves confirmed the stability and reliability of the model. DCA showed that the net clinical effect of the histogram was superior to that of the TNM staging system, while CIC highlighted the potentially large clinical impact of the model.ConclusionsThe developed Nomogram provides a powerful and accurate tool for clinicians to assess the risk of treatment failure after radical surgery in patients with stage III colon cancer

    PAX8: a sensitive and specific marker to identify cancer cells of ovarian origin for patients prior to neoadjuvant chemotherapy

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    BACKGROUND: Neoadjuvant chemotherapy followed by cytoreduction surgery has been used where an accurate cytologic or pathologic diagnosis is usually required before the initiation of neoadjuvant chemotherapy. However, it is difficult to make definitive diagnosis of presence of cancer cells, particularly gynecologic versus non-gynecologic origin, from those ascites specimens due to the absence of specific biomarkers of gynecologic cancers. In the present study, we evaluated if, in addition to the routine morphologic diagnosis, the biomarker PAX8 could be useful in recognition of ovarian epithelial cancer cells prior to the neoadjuvant chemotherapy. METHODS: Two hundred and two cytology specimens including 120 pretreatment ovarian cancer samples, 60 benign controls, and 22 malignant non-gynecologic cases were studied. All cytology slides were morphologically reviewed in a blinded fashion without knowing corresponding pathology diagnosis, if present. A total of 168 cytology specimens with a cell block were stained with PAX8 and Calretinin. These included patients with potential for ovarian cancer neoadjuvant chemotherapy (n = 96), metastatic cancers (n = 22), and benign controls (n = 50). RESULTS: Among the 96 ascitic samples prior to neoadjuvant chemotherapy, 76 (79%) showing morphologic features consistent with cancers of ovarian primary were all PAX+/Calretinin-. The remaining 20 (21%) cases were positive for adenocarcinoma, but morphologically unable to be further classified. Among the 22 metastatic cancers into the pelvis, one case with PAX8+/Calretinin- represented a renal cell carcinoma and the remaining 21 PAX8-/Calretinin- metastatic cancers were either breast metastasis (n = 4) and the metastasis from gastrointestinal tract (n = 17). Among the 50 benign control pelvic washing cases, 5 PAX8+/Calretinin-cases represented endosalpingiosis (n = 4) and endometriosis (n = 1), 25 PAX8-/Calretinin + cases showed reactive mesothelial cells, and the remaining 20 specimens with PAX8-/Calretinin- phenotype typically contained inflammatory or blood cells without noticeable diagnostic epithelia. CONCLUSIONS: PAX8 identifies all Müllerian derived benign or malignant epithelia. When combining with Calretinin, PAX8 is a sensitive marker to diagnose the carcinomas of ovarian origin, which will be ideal to be used for those patients with a possible advanced ovarian cancer prior to receiving neoadjuvant chemotherapy

    Functional Characterization of BoaMYB51s as Central Regulators of Indole Glucosinolate Biosynthesis in Brassica oleracea var. alboglabra Bailey

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    R2R3-MYB transcription factor MYB51 is known to control indole glucosinolate (indole GSL) biosynthesis in Arabidopsis. Here, two copies of BoaMYB51 have been isolated in Chinese kale (Brassica oleracea var. alboglabra Bailey), designated BoaMYB51.1 and BoaMYB51.2, which exhibit overlapping but distinct expression levels among different organs and respond to signaling molecules in a similar pattern. It has been demonstrated a structural and functional conservation between BoaMYB51s and AtMYB51 by phylogenetic analysis, complementation studies and transient expression assay. To further investigate the transcriptional mechanism, we identified the transcriptional activation domain (TAD) and putative interacting proteins of BoaMYB51s by means of yeast (Saccharomyces cerevisiae) two hybrid. Using tobacco (Nicotiana benthamiana) transient expression assay, we confirmed that the carboxy-end is required for transcriptional activation activity of BoaMYB51s. In addition, several BoaMYB51-interacting proteins have been identified by yeast two-hybrid screening. These results provide important insights into the molecular mechanisms by which MYB51 transcriptionally regulates indole GSL biosynthesis

    Highly branched poly(β-amino ester) delivery of minicircle DNA for transfection of neurodegenerative disease related cells

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    Current therapies for most neurodegenerative disorders are only symptomatic in nature and do not change the course of the disease. Gene therapy plays an important role in disease modifying therapeutic strategies. Herein, we have designed and optimized a series of highly branched poly(β-amino ester)s (HPAEs) containing biodegradable disulfide units in the HPAE backbone (HPAESS) and guanidine moieties (HPAESG) at the extremities. The optimized polymers are used to deliver minicircle DNA to multipotent adipose derived stem cells (ADSCs) and astrocytes, and high transfection efficiency is achieved (77% in human ADSCs and 52% in primary astrocytes) whilst preserving over 90% cell viability. Furthermore, the top-performing candidate mediates high levels of nerve growth factor (NGF) secretion from astrocytes, causing neurite outgrowth from a model neuron cell line. This synergistic gene delivery system provides a viable method for highly efficient non-viral transfection of ADSCs and astrocytes
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