RESUMO
A series of ß-ketoenamines was synthesized from various phenacyl sulfoxides bearing 1-methyl-1H-tetrazole and oximes in moderate to excellent yields. The proposed mechanism involved the generation of α-sulfines from sulfoxides through thermolytic elimination, regiospecific formal [3 + 2] annulations, and elimination of SO2. This protocol provides convenient access to a variety of synthetically valuable N-unprotected ß-enaminones with absolute Z selectivity.
RESUMO
We demonstrated all-silicon IQ modulators (IQMs) operating at 120-GBaud 16-QAM with suitable bandwidth, and output power. We required optical signal-to-noise-ratio (rOSNR) that have promising potential to be used in 800-Gbps small-form-factor pluggable transceivers for data center interconnection. First, we tested an IQM chip using discrete drivers and achieved a per-polarization TX output power of -18.74 dBm and an rOSNR of 23.51â dB over a 100-km standard SMF. Notably, a low BER of 1.4e-3 was obtained using our SiP IQM chip without employing nonlinear compensation, optical equalization, or an ultra-wide-bandwidth, high-ENOB OMA. Furthermore, we investigated the performance of a 3D packaged transmitter by emulating its frequency response using an IQM chip, discrete drivers, and a programmable optical filter. With a laser power of 17 dBm, we achieved a per-polarization output power of -15.64 dBm and an rOSNR of 23.35â dB.
RESUMO
Liver cancer is generally considered the leading cause of cancer deaths worldwide, and hepatocellular carcinoma (HCC) contributes to more than 90% of liver cancers. The altered lipid metabolism for rapid cancer cell growth and tumor formation has been frequently proven. In this study, an ambient ionization mass spectrometry technique, rapid evaporative ionization mass spectrometry (REIMS) using a monopolar electric knife, called iKnife, was systematically optimized and employed for ex vivo analysis of 12 human HCC tumor tissue specimens together with the paired paracancerous tissue (PT) and noncancerous liver tissue (NCT) specimens. Nine free fatty acids and 34 phospholipids were tentatively identified according to their extract masses and/or tandem mass spectra. With the help of statistical methods, 7 free fatty acids and 10 phospholipids were distributed differently in 3 types of liver tissue specimens (95% confidence interval). The box plots showed these characterized lipid metabolites varied in PT, HCC, and NCT. Compared with PT and NCT, the upregulations of four common fatty acids FA 18:0, FA 20:4, FA 16:0, and FA 18:1, together with phospholipids PC 36:1, PE 38:3, PE (18:0/20:4), PA (O-36:1), PC (32:1), PC 32:0, PE 34:0, and PC (16:0/18:1), were found in HCC specimens. The sensitivity and specificity of the established statistic model for real-time HCC tumor diagnosis were 100% and 90.5%, respectively. This study demonstrated that the described REIMS technique is a potential method for rapid lipidomic analysis and characterization of HCC tumor tissue.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Lipidômica , Neoplasias Hepáticas/diagnóstico , Ácidos Graxos não Esterificados , Fosfolipídeos/química , Espectrometria de Massas em TandemRESUMO
A layer of glycocalyx covers the vascular endothelium serving important protective and homeostatic functions. The objective of this study was to determine if breakdown of the endothelial glycocalyx (eGC) occurs during malaria infection in children. Measures of eGC integrity, endothelial activation, and microvascular reactivity were prospectively evaluated in 146 children: 44 with moderately severe malaria (MSM), 42 with severe malaria (SM), and 60 healthy controls (HC). Biochemical measures of eGC integrity included plasma syndecan-1 and total urinary glycosaminoglycans (GAG). Side-stream dark field imaging was used to quantitatively assess integrity of eGC. Plasma angiopoietin-2 (Ang-2) was measured as a marker of endothelial activation and also as a possible mediator of eGC breakdown. Our results show that urinary GAG, syndecan-1, and Ang-2 were elevated in patients with MSM and SM compared with HC. Syndecan-1 and GAG levels correlated significantly with each other and with plasma Ang-2. The eGC breakdown products also inversely correlated significantly with hemoglobin and platelet count. In the MSM group, imaging results provided further evidence for eGC degradation. Although not correlated with markers of eGC degradation, vascular function (assessed by non-invasive near infrared spectroscopy [NIRS]) demonstrated reduced microvascular reactivity, particularly affecting the SM group. Our findings provide further evidence for breakdown of eGC in falciparum malaria that may contribute to endothelial activation and adhesion of parasitized red blood cells, with reduced nitric oxide formation, and vascular dysfunction.
Assuntos
Células Endoteliais/metabolismo , Glicocálix/metabolismo , Malária Falciparum/metabolismo , Malária Falciparum/patologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Microcirculação , TanzâniaRESUMO
BACKGROUND: Colorectal juvenile polyps are rare and generally considered benign in adults. Carcinogenesis or neoplastic changes are rarely mentioned in the literature. We systematically evaluated the characteristics and potential malignancy of colorectal juvenile polyps in adults. METHODS: We retrospectively reviewed the medical records of 103 adults diagnosed with colorectal juvenile polyps from September 2007 to May 2020 at our hospital. The characteristics, endoscopic findings, occurrence of intraepithelial neoplasia, carcinogenesis and diagnostic value of chicken skin mucosa (CSM) were analyzed. RESULTS: The average age of patients with juvenile polyps was 43.2 years (range, 19 to 78 years). A total of 101 patients (101/103, 98.1%) had a single juvenile polyp, and two patients had multiple polyps (107 polyps in total). Polyp sizes ranged from 0.5 to 5 cm. One (1/107, 0.9%) juvenile polyp was cancerous, and 7 (7/107, 6.5%) developed low-grade intraepithelial neoplasia. Neoplasia and cancerization did not appear in the two patients with multiple polyps. A 27-year-old female had a 2-cm polyp with well-differentiated adenocarcinoma in the mucosa in the sigmoid colon with erosion on the surface. CSM was observed adjacent to 17 polyps, which were all located in the rectum and sigmoid colon, and one polyp showed low-grade intraepithelial neoplasia. CONCLUSIONS: Colorectal juvenile polyps occur in a wide range of locations and in variable sizes and numbers. These polyps are solitary in most patients and have neoplastic potential. CSM is not a tumorigenic marker in colorectal juvenile polyps and usually occurs in the distant colorectum. Colorectal juvenile polyps in adults may progress from low-grade intraepithelial neoplasia to high-grade intraepithelial neoplasia and then to carcinoma and should be treated when discovered and regularly followed as colorectal adenomas.
Assuntos
Adenoma , Pólipos do Colo , Neoplasias Colorretais , Adenoma/diagnóstico , Adulto , Idoso , Pólipos do Colo/patologia , Colonoscopia , Neoplasias Colorretais/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
PURPOSE: This study aimed to evaluate the effect of reinforced education (RE) by short message service (SMS) on the bowel preparation quality of patients undergoing colonoscopy. METHODS: Randomized controlled trials (RCTs), conducted on the effect of RE by SMS on bowel preparation for colonoscopy from inception to November 1, 2021, were queried from databases, including PubMed, Web of Science, the Cochrane Library, and EMBASE. After extracting the data, meta-analysis was conducted using Review Manager Software version 5.3. RESULTS: A total of seven RCTs with 5889 patients were subjected to meta-analysis. The rate of adequate bowel preparation in the SMS group (81.7%) was significantly higher than that in the control group (75.7%) (RR: 1.10, 95% CI: 1.03-1.17, p < 0.01). Four studies suggested that RE by SMS significantly reduced the non-attendance rate of patients for scheduled colonoscopy (RR: 0.74, 95% CI: 0.56-0.99, p < 0.05). CONCLUSION: RE by SMS for patients undergoing colonoscopy can significantly improve the quality of bowel preparation and decrease the non-attendance rate of patients for scheduled colonoscopy.
Assuntos
Envio de Mensagens de Texto , Catárticos/uso terapêutico , Colonoscopia , Escolaridade , HumanosRESUMO
Exosomes show potential for treating patients with spinal cord injury (SCI) in clinical practice, but the underlying repair mechanisms remain poorly understood, and biological scaffolds available for clinical transplantation of exosomes have yet to be explored. In the present study, we demonstrated the novel function of Gel-Exo (exosomes encapsulated in fibrin gel) in promoting behavioural and electrophysiological performance in mice with SCI, and the upregulated neural marker expression in the lesion site suggested enhanced neurogenesis by Gel-Exo. According to the RNA-seq results, Vgf (nerve growth factor inducible) was the key regulator through which Gel-Exo accelerated recovery from SCI. VGF is related to myelination and oligodendrocyte development according to previous reports. Furthermore, we found that VGF was abundant in exosomes, and Gel-Exo-treated mice with high VGF expression indeed showed increased oligodendrogenesis. VGF was also shown to promote oligodendrogenesis both in vitro and in vivo, and lentivirus-mediated VGF overexpression in the lesion site showed reparative effects equal to those of Gel-Exo treatment in vivo. These results suggest that Gel-Exo can thus be used as a biocompatible material for SCI repair, in which VGF-mediated oligodendrogenesis is the vital mechanism for functional recovery.
Assuntos
Exossomos , Traumatismos da Medula Espinal , Animais , Exossomos/metabolismo , Fibrina/metabolismo , Fibrina/uso terapêutico , Camundongos , Neurogênese , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/patologiaRESUMO
PURPOSE: Colorectal neuroendocrine carcinomas (CRC-NECs) are rare, comprising < 1% of colorectal cancers. This study aimed to assess the incidence, clinicopathologic characteristics, prognostic factors, and treatment outcomes of CRC-NEC. METHODS: We analysed the Surveillance, Epidemiology, and End Results (SEER) database to identify patients from 20 to 74 years old diagnosed with CRC-NEC or common CRC (non-NEC) during 2004-2013. Log-rank testing was conducted to assess survival differences. A competing-risks regression model was used to adjust for covariate effects in the propensity score-matched (PSM) cohort, and adjusted hazard ratios (HRs) were calculated for the raw and PSM cohorts. RESULTS: We identified 67,484 patients (344 CRC-NEC and 67,140 non-NEC). Lymph node metastasis (LNM) was more common in CRC-NEC (75.29%, n = 259) than in non-NEC (51.53%, n = 34,600) (P < 0.001); 56.40% (n = 194) of CRC-NECs were located on the right side, while 18.31% (n = 63) were located on the left side, with a statistically significant difference in distribution (P < 0.001) compared to that in non-NEC CRC. Multivariate analysis indicated that a left-side location was an independent adverse prognostic factor for CRC-NEC (P = 0.043). CRC-NEC had the poorest cancer-specific survival (median CSS, 9.0 months) among assessed cancers, even poorer than that of signet ring cell cancer (median CSS, 24.0 months). However, both radical operation (P = 0.007) and chemotherapy (P = 0.008) were beneficial for CSS. CONCLUSION: NEC is a rare and extremely aggressive tumour with a poor prognosis. Right-side NEC has a better prognosis than left-side NEC. Early diagnosis, radical surgery, and chemotherapy are imperative for improving survival.
Assuntos
Carcinoma Neuroendócrino , Carcinoma de Células em Anel de Sinete , Neoplasias do Colo , Adulto , Idoso , Carcinoma Neuroendócrino/epidemiologia , Carcinoma de Células em Anel de Sinete/epidemiologia , Carcinoma de Células em Anel de Sinete/patologia , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Pontuação de Propensão , Reto/patologia , Programa de SEER , Adulto JovemRESUMO
In this Letter, we experimentally demonstrate a 50Gb/s/λ four-level pulse amplitude modulation-based passive optical network system with a 10 G class receiver. A memory polynomial equalizer (MPE) combined with a decision feedback equalizer (DFE) is applied to eliminate channel distortions in the system. To further improve the performance of the MPE-DFE, for the first time, to the best of our knowledge, a low-complexity hybrid decision scheme (HDS) is proposed, which consists of single-symbol decision (SSD) and multi-symbol decision (MSD). The SSD is exactly the conventional hard decision based on minimum Euclidean distance, whereas MSD is based on a simplified maximum likelihood detection principle with M-algorithm. In terms of complexity, MSD requires 19.1% more multiplications than SSD, but the symbol number of MSD only accounts for less than 20% of the total signal frame when the received optical power is greater than -27dBm. Experimental results show that the proposed MPE-DFE with HDS achieves a 0.7 dB and 1.3 dB sensitivity gain compared with conventional SSD, and up to 35.4 dB and 31.4 dB link power budget, regarding the forward error correction threshold of 10-2 and 10-3, respectively.
RESUMO
In this Letter, we propose a digital signal processing (DSP) -aided technique to optimize the power ratio among users for orthogonal frequency division multiplexing (OFDM) -based non-orthogonal multiple access (NOMA) in an integrated optical fiber and millimeter wave (mmWave) wireless communication system. In this way, a central or distributed unit can leverage the proposed techniques to maintain the uniformity of the signal-to-noise ratios (SNRs) among subcarriers without requiring any channel information feedback. The proposed mechanism can facilitate the power allocation management by treating all subcarriers equally as an independent channel. As an illustration, multiple NOMA scenarios, in which a near user with 10 km fiber transmission and far user with either longer fiber distance or additional wireless propagation, are experimentally investigated. Experimental results demonstrate that when the conventional OFDM-NOMA without the proposed DSP-aided technique is used, the optimal power ratios vary rapidly when the subcarrier quality index changes due to high-frequency fading in a mmWave radio over fiber (RoF) system, whereas, by using the proposed techniques, including both orthogonal circulant matrix transform and discrete Fourier transform, the optimal power ratios on all effective subcarriers are optimized at the same level and the users' performance is significantly improved.
RESUMO
Cerebral malaria (CM) from Plasmodium falciparum infection is associated with endothelial dysfunction and parasite sequestration. The glycocalyx (GCX), a carbohydrate-rich layer lining the endothelium, is crucial in vascular homeostasis. To evaluate the role of its loss in the pathogenesis of pediatric CM, we measured GCX degradation in Tanzanian children with World Health Organization-defined CM (n = 55), uncomplicated malaria (UM; n = 20), and healthy controls (HCs; n = 25). Urine GCX breakdown products [glycosaminoglycans (GAGs)] were quantified using dimethylmethylene blue (DMMB) and liquid chromatography-tandem mass spectrometry assays. DMMB-GAG and mass spectrometry (MS)-GAG (g/mol creatinine) were increased in CM and UM compared with HCs (P < 0.001), with no differences in DMMB-GAG and MS-GAG between CM and UM children or between those with and without a fatal outcome. In CM survivors, urinary GCX DMMB-GAG normalized by d 3. After adjusting for disease severity, DMMB-GAG was significantly associated with parasitemia [partial correlation coefficient (Pcorr) = 0.34; P = 0.01] and plasma TNF (Pcorr = 0.26; P = 0.04) and inversely with plasma and urine NO oxidation products [Pcorr = -0.31 (P = 0.01) and Pcorr = -0.26 (P = 0.03), respectively]. GCX breakdown is increased in children with falciparum malaria, with similar elevations in CM and UM. Endothelial GCX degradation may impair endothelial NO production, exacerbate adhesion-molecule expression, exposure, and parasite sequestration, and contribute to malaria pathogenesis.-Yeo, T. W., Bush, P. A., Chen, Y., Young, S. P., Zhang, H., Millington, D. S., Granger, D. L., Mwaikambo, E. D., Anstey, N. M., Weinberg, J. B. Glycocalyx breakdown is increased in African children with cerebral and uncomplicated falciparum malaria.
Assuntos
Glicocálix/metabolismo , Malária Cerebral/metabolismo , Malária Falciparum/metabolismo , Biomarcadores/urina , Criança , Pré-Escolar , Feminino , Glicosaminoglicanos/metabolismo , Glicosaminoglicanos/urina , Humanos , Lactente , Malária Falciparum/patologia , Malária Falciparum/urina , Masculino , Azul de Metileno/análogos & derivados , Parasitemia , TanzâniaRESUMO
BACKGROUND: Interactions between the endothelium and infected erythrocytes play a major role in the pathogenesis of falciparum malaria, with microvascular dysfunction and parasite sequestration associated with worsening outcomes. The glycocalyx is a carbohydrate-rich layer that lines the endothelium, with multiple roles in vascular homeostasis. The role of the glycocalyx in falciparum malaria and the association with disease severity has not been investigated. METHODS: We prospectively enrolled Indonesian inpatients (aged ≥18 years) with severe (SM) or moderately severe (MSM) falciparum malaria, as defined by World Health Organization criteria, and healthy controls (HCs). On enrollment, blood and urine samples were collected concurrently with measurements of vascular nitric oxide (NO) bioavailability. Urine was assayed for glycocalyx breakdown products (glycosaminoglycans) using a dimethylmethylene blue (GAG-DMMB) and liquid chromatography-tandem mass spectrometry (GAG-MS) assay. RESULTS: A total of 129 patients (SM = 43, MSM = 57, HC=29) were recruited. GAG-DMMB and GAG-MS (g/mol creatinine) were increased in SM (mean, 95% confidence interval: 3.98, 2.44-5.53 and 6.82, 5.19-8.44) compared to MSM patients (1.78, 1.27-2.29 and 4.87, 4.27-5.46) and HCs (0.22, 0.06-0.37 and 1.24, 0.89-1.59; P < 0.001). In SM patients, GAG-DMMB and GAG-MS were increased in those with a fatal outcome (n = 3; median, interquartile range: 6.72, 3.80-27.87 and 12.15, 7.88-17.20) compared to survivors (n = 39; 3.10, 0.46-4.5 and 4.64, 2.02-15.20; P = 0.03). Glycocalyx degradation was significantly associated with parasite biomass in both MSM (r = 0.48, GAG-DMMB and r = 0.43, GAG-MS; P < 0.001) and SM patients (r = 0.47, P = 0.002 and r = 0.33, P = 0.04) and inversely associated with endothelial NO bioavailability. CONCLUSIONS: Increased endothelial glycocalyx breakdown is associated with severe disease and a fatal outcome in adults with falciparum malaria.
Assuntos
Endotélio Vascular/metabolismo , Glicocálix/metabolismo , Interações Hospedeiro-Parasita , Malária Falciparum/mortalidade , Malária Falciparum/fisiopatologia , Adolescente , Adulto , Endotélio Vascular/microbiologia , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Feminino , Glicosaminoglicanos/urina , Humanos , Indonésia , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/sangue , Plasmodium falciparum , Estudos Prospectivos , Adulto JovemRESUMO
Alteration in RNA splicing is implicated in carcinogenesis and progression. Mutations in spliceosome genes and alternative splicing of other genes have been noted in chronic lymphocytic leukaemia (CLL), a common B cell malignancy with heterogeneous outcomes. We previously demonstrated that differences in the amount of SET oncoprotein (a physiological inhibitor of the serine/threonine phosphatase, PP2A) is associated with clinical aggressiveness in patients with CLL. It is unknown if alternative splicing of gene transcripts regulating kinases and phosphatases affects disease pathobiology and CLL progression. We show here for the first time that mRNA levels of the alternatively spliced SET isoforms, SETA and SETB (SETα and SETß), significantly correlate with disease severity (overall survival and time-to-first-treatment) in CLL patients. In addition, we demonstrate that relative increase of SETA to SETB mRNA can discriminate patients with a more aggressive disease course within the otherwise favourable CLL risk classifications of IGHV mutated and favourable hierarchical fluorescence in situ hybridisation groups. We validate our finding by showing comparable relationships of SET mRNA with disease outcomes using samples from an independent CLL cohort from a separate institution. These findings indicate that alternative splicing of SET, and potentially other signalling cascade molecules, influences CLL biology and patient outcomes.
Assuntos
Chaperonas de Histonas , Leucemia Linfocítica Crônica de Células B , Proteínas de Neoplasias , RNA Mensageiro , RNA Neoplásico , Fatores de Transcrição , Adulto , Idoso , Idoso de 80 Anos ou mais , Processamento Alternativo , Proteínas de Ligação a DNA , Intervalo Livre de Doença , Feminino , Chaperonas de Histonas/biossíntese , Chaperonas de Histonas/genética , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/mortalidade , Leucemia Linfocítica Crônica de Células B/terapia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , Taxa de Sobrevida , Fatores de Transcrição/biossíntese , Fatores de Transcrição/genéticaRESUMO
We propose and experimentally demonstrate a proactive real-time interference avoidance scheme using SARSA reinforcement learning (RL) in a millimeter-wave over a fiber mobile fronthaul system. The RL consists of three core factors, including state, action, and reward. The state is defined as a discretized value from the center frequency, the left, right, and center sub-EVM of the signal. We use five actions to shift the signal frequency in the proposed scheme, which is -20, -10, 0, 10, and 20 MHz, for the RL agent to choose the action to avoid the dynamic interference. For the agent to learn from the experience, the reward is defined as the log value of BER difference between the past and the present state. The RL-based approach is an online learning algorithm, which can learn in real time based on environmental feedback. Besides, the agent can learn from past experience owing to the Q-value table, which makes it act intelligently when facing a similar situation again. We verify the capability of the proposed scheme under both fixed and dynamic interference scenarios. The agent demonstrates an efficient intelligent mechanism to avoid the interference, which provides a promising solution for proactive interference mitigation in the 5 G mobile fronthaul network.
RESUMO
We propose and experimentally demonstrate a novel digital post-linearization algorithm for the mobile fronthaul system employing bandwidth-efficient multiple intermediate frequency-over-fiber technology and a low-cost directly-modulated laser (DML). The proposed linearization algorithm is distinguished for blind adaption, the absence of training signal, or prior knowledge of the transmission channel. Particularly, it provides a closed-form solution for the estimation of optimal linearizer coefficients, leading to a non-iterative mode without convergence restrictions. In our experiments, one and nine 200 MHz 64-QAM OFDM IF signals (or channels) are transmitted over a 10 km single-mode fiber link using a DML. In both cases (one and nine IF channels), the linearization performance of the proposed algorithm is experimentally validated in terms of the reduction (>8 dB) of the adjacent channel leakage ratio, decrease (>10 dB) of error vector magnitude (EVM), and an increase (>9 dB) of EVM-compliant input RF power range.
RESUMO
A novel Gram-positive bacterium, designated strain YIM PH21725T, was isolated from a sample of rhizospheric soil of Panaxnotoginseng cultivated in Anning, Yunnan. The strain contained meso-diaminopimelic acid in the cell-wall peptidoglycan. The main fatty acids identified were C17â:â0, iso-C15â:â0, iso-C16â:â0 and C16â:â0. The main menaquinone was MK-9 (H4). The polar lipids included phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phospholipids and phospholipids of an unidentified structure containing glucosamine. The G+C content of genomic DNA was 69.43 mol%. On the basis of its 16S rRNA gene sequence, strain YIM PH21725T should belong to the genus Amycolatopsis, and was closely related to Amycolatopsis sulphurea DSM 46092T (98.57â%), Amycolatopsis jejuensis JCM13280T (97.27â%), Amycolatopsis jiangsuensis KCTC 19885T (96.88â%) and Amycolatopsis ultiminotia JCM 16989T (96.8â%). The phenotypic, chemotaxonomic, phylogenetic and digital DNA-DNA hybridization results clearly indicated that strain YIM PH21725T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsispanacis sp. nov. is proposed. The type strain is YIM PH21725T (=CCTCC AA 2017044T=KCTC 49031T=DSM 105902T).
Assuntos
Actinobacteria/classificação , Panax notoginseng/microbiologia , Filogenia , Microbiologia do Solo , Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rizosfera , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
BACKGROUND: Pathogenesis of severe Plasmodium vivax malaria is poorly understood. Endothelial dysfunction and reduced nitric oxide (NO) bioavailability characterize severe falciparum malaria, but have not been assessed in severe vivax malaria. METHODS: In patients with severe vivax malaria (n = 9), patients with nonsevere vivax malaria (n = 58), and healthy controls (n = 79), we measured NO-dependent endothelial function by using reactive hyperemia-peripheral arterial tonometry (RH-PAT) and assessed associations with arginine, asymmetric dimethylarginine (ADMA), and hemolysis. RESULTS: The L-arginine level and the L-arginine to ADMA ratio (a measure of L-arginine bioavailability) were reduced in patients with severe vivax malaria and those with nonsevere vivax malaria, compared with healthy controls (median L-arginine level, 65, 66, and 98 µmol/mL, respectively [P = .0001]; median L-arginine to ADMA ratio, 115, 125, and 187, respectively [P = .0001]). Endothelial function was impaired in proportion to disease severity (median RH-PAT index, 1.49, 1.73, and 1.97 in patients with severe vivax malaria, those with nonsevere vivax malaria, and healthy controls, respectively; P = .018) and was associated with the L-arginine to ADMA ratio. While the posttreatment fall in hemoglobin level was greater in severe vivax malaria as compared to nonsevere vivax malaria (2.5 vs 1 g/dL; P = .0001), markers of intravascular hemolysis were not higher in severe disease. CONCLUSIONS: Endothelial function is impaired in nonsevere and severe vivax malaria, is associated with reduced L-arginine bioavailability, and may contribute to microvascular pathogenesis. Severe disease appears to be more associated with extravascular hemolysis than with intravascular hemolysis.
Assuntos
Arginina/sangue , Células Endoteliais/fisiologia , Hemólise , Malária Vivax/patologia , Óxido Nítrico/metabolismo , Adolescente , Adulto , Idoso , Disponibilidade Biológica , Estudos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto JovemRESUMO
In an intensity-modulation direct-detection (IMDD) orthogonal frequency division multiplexing (OFDM) signal format, radio frequency (RF) power fading produces non-uniform receiving performance among the subcarriers due to chromatic dispersion. Hence each subscriber experiences distinct quality of service (QoS) in conventional frequency division multiple access (FDMA). In this paper, a multicarrier code division multiple access (MC-CDMA) signal along with multicode interference (MCI) cancellation process is proposed and experimentally demonstrated to enhance the receiving performance in an IMDD long reach passive optical network (LR-PON). With the proposed scheme, the receiving performance of each subcarrier can be equalized so that a universal transmitter design at central office (CO) can support all the subscribers with their locations ranging from back-to-back to 100 km. Our experimental results also reveal that, even under 20 dB RF power fading, the proposed scheme can still provide over 21.7 dB power budget and only approximately 2 dB sensitivity deviation is observed in an IMDD LR-PON system.
RESUMO
Eight new fungal polyketides named koningiopisins A-H (1-8) and four previously known polyketides (9-12) were isolated from the endophytic fungus Trichoderma koningiopsis YIM PH 30002. Their structures were elucidated using extensive spectral data interpretation, and their antifungal and synergistic activities were also evaluated. Koningiopisin C (3) exhibited in vitro antifungal activity against the phytopathogenic fungus Plectosphaerella cucumerina with an MIC of 16 µg/mL. Although the antifungal activities of single compounds were not obvious, a mixture of six compounds (4-9) exhibited potent synergistic antifungal activity against P. cucumerina with an MIC of 16 µg/mL, and the antifungal activity of the mixture of any two compounds with a 1:1 ratio was better than that observed from the individual compound. The synergistic biological activity of the metabolites in YIM PH 30002 demonstrates the significant ecological function of the endophyte for its host plant, and provides additional insight into the search for and development of agents for biological control.
Assuntos
Antifúngicos/isolamento & purificação , Policetídeos/isolamento & purificação , Trichoderma/química , Antifúngicos/química , Antifúngicos/farmacologia , Ascomicetos/efeitos dos fármacos , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana , Estrutura Molecular , Policetídeos/química , Policetídeos/farmacologiaRESUMO
A simple polarization division multiplexed (PDM) multiband direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) long reach passive optical network (LR-PON) with net data rate over 210 Gb/s on single wavelength channel is proposed and experimentally demonstrated with self-polarization diversity technique. The proposed self-polarization diversity function is realized at a powered remote node with all passive components to achieve cost-effectiveness and simultaneously double both the channel capacity and subscriber numbers. Meanwhile, this architecture retains the simplicity of direct-detection single receiver-end without any hardware or software modification at the optical network units. The measured power penalty of the proposed PDM multiband DDO-OFDM LR-PON is 0.8 dB over 100 km transmission with respect to that of the ordinary single polarization scheme at a specified forward error correction threshold.