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1.
J Chromatogr A ; 1720: 464811, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38490143

RESUMO

A novel silica stationary phase was designed and prepared through thiol-epoxy click chemistry for supercritical fluid chromatography (SFC). The developed stationary phase was characterized by elemental analysis, Fourier transform infrared spectrometry and solid-state 13C/CP MAS NMR spectroscopy. In order to evaluate the chromatographic performance and retention mechanisms of the prepared column, a variety of alkaloids were used, including indoles, isoquinolines, pyrrolidines, piperidines, quinolizidines and organic amines. The stationary phase showed more symmetrical peak shapes and better performance for these compounds compared to the conventional SFC stationary phases. The investigations on the effects of pressure and temperature on retention provided information that the selectivity of the compounds can be improved by changing the density of the supercritical fluids. Moreover, it shows improved separation efficiency of three natural products with alkaloids as the main components at high sample loading. In conclusion, the developed stationary phase could offer flexible selectivity toward alkaloids and complex samples.


Assuntos
Alcaloides , Cromatografia com Fluido Supercrítico , Cromatografia com Fluido Supercrítico/métodos , Compostos de Sulfidrila , Temperatura , Aminas , Dióxido de Silício/química
2.
Heliyon ; 10(5): e26765, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38434420

RESUMO

Backgrounds: Global fertility rates continue to decline and sperm quality is a prime factor affecting male fertility. Both extreme cold and heat have been demonstrated to be associated with decreased sperm quality, but no epidemiological studies have considered human adaptation to long-term temperature. Our aim was to conduct a multi-center retrospective cohort study to investigate exposure-response relationship between temperature anomaly (TA) that deviate from long-term climate patterns and sperm quality. Methods: A total of 78,952 semen samples measured in 33,234 donors from 6 provincial human sperm banks in China were collected. This study considered heat and cold acclimatization to prolonged exposure in humans and explored the exposure-response relationship between TAs and sperm quality parameters (sperm concentrations, sperm count, progressive motility, progressive sperm count, total motility and total motile sperm count) during the hot and cold seasons, respectively. Linear mixed models and generalized linear models were built separately for specific centers to pool in a meta-analysis to obtain the pooled effect of TA on sperm quality, considering repeated measurements data structure and spatial heterogeneity. Results: We identified an inverted U-shaped exposure-response relationship between TA and sperm quality during the hot season. Significant negative effect of anomalous cold on sperm quality during the hot season was found after additional adjustment for Body mass index, marital status and childbearing history. The heat-related TA in hot season was significantly negatively associated with sperm concentration, progressive sperm count and total motile sperm count (all P-values<0.05). After adjusting the relative humidity, the cold-related TA in cold season was negatively associated with the sperm total motility (P-values<0.05). Conclusions: Our results suggest both heat-related and cold-related TAs are associated with decreased sperm quality. The findings highlight the importance of reducing exposure to anomalous temperatures to protect male fertility.

3.
Chem Commun (Camb) ; 60(27): 3649-3652, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38372355

RESUMO

Herein, silica microspheres with ordered mesopores are synthesized and applied as a stationary phase for supercritical fluid chromatography (SFC). The excellent particle monodispersity and pore orderliness coupled with the rapid analytes diffusion of the supercritical fluid lead to an ultra-high column efficiency of 340 000 plate per m.

4.
Micromachines (Basel) ; 14(12)2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38138398

RESUMO

We present here a performance comparison of quantum-dash (Qdash) semiconductor amplifiers (SOAs) with three, five, eight, and twelve InAs dash layers grown on InP substrates. Other than the number of Qdash layers, the structures were identical. The eight-layer Qdash SOA gave the highest amplified spontaneous emission power (4.3 dBm) and chip gain (26.4 dB) at 1550 nm, with a 300 mA CW bias current and at 25 °C temperature, while SOAs with fewer Qdash layers (for example, three-layer Qdash SOA), had a wider ASE bandwidth (90 nm) and larger 3 dB gain saturated output power (18.2 dBm) in a shorter wavelength range. The noise figure (NF) of the SOAs increased nearly linearly with the number of Qdash layers. The longest gain peak wavelength of 1570 nm was observed for the 12-layer Qdash SOA. The most balanced performance was obtained with a five-layer Qdash SOA, with a 25.4 dB small-signal chip gain, 15.2 dBm 3 dB output saturated power, and 5.7 dB NF at 1532 nm, 300 mA and 25 °C. These results are better than those of quantum well SOAs reported in a recent review paper. The high performance of InAs/InP Qdash SOAs with different Qdash layers shown in this paper could be important for many applications with distinct requirements under uncooled scenarios.

5.
Se Pu ; 41(10): 866-878, 2023 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-37875409

RESUMO

Supercritical fluid chromatography (SFC) is an environment-friendly and efficient column chromatography technology that was developed to expand the application range of high performance liquid chromatography (HPLC) using a supercritical fluid as the mobile phase. A supercritical fluid has a temperature and pressure that are above the critical values as well as relatively dynamic characteristics that are between those of a gas and liquid. Supercritical fluids combine the advantages of high solubility and diffusion, as their diffusion and viscosity coefficients are equivalent to those of a gas, while maintaining a density that is comparable with that of a liquid. Owing to the remarkable compressibility of supercritical fluids, analyte retention in SFC is significantly influenced by the density of the mobile phase. Thus, the column temperature and back pressure are crucial variables that regulate analyte retention in SFC. Increasing the back pressure can increase the density and solubility of the mobile phase, leading to reductions in retention time. The column temperature can affect selectivity and retention, and the degree to which different analytes are affected by this property varies. On the one hand, increasing the temperature reduces the density of the mobile phase, thereby extending the retention time of the analytes; on the other hand, it can also increase the energy of molecules, leading to a shorter retention time of the analyte on the stationary phase. CO2, the most widely employed supercritical fluid to date, presents moderate critical conditions and, more importantly, is miscible with a variety of polar organic solvents, including small quantities of water. In comparison with the mobile phases used in normal-phase liquid chromatography (NPLC) and reversed-phase liquid chromatography (RPLC), the mobile phase for SFC has a polarity that can be extended over a wide range on account of its extensive miscibility. The compatibility of the mobile phase determines the diversity of the stationary phase. Nearly all stationary phases for HPLC, including the nonpolar stationary phases commonly used for RPLC and the polar stationary phases commonly used for NPLC, can be applied to SFC. Because all stationary phases can use the same mobile-phase composition, chromatographic columns with completely different polarities can be employed in SFC. The selectivity of SFC has been effectively expanded, and the technique can be used for the separation of diverse analytes ranging from lipid compounds to polar compounds such as flavonoids, saponins, and peptides. The choice of stationary phase has a great impact on the separation effect of analytes in SFC. As new stationary phases for HPLC are constantly investigated, specialized stationary phases for SFC have also been continuously developed. Researchers have discovered that polar stationary phases containing nitrogen heterocycles such as 2-EP and PIC are highly suitable for SFC because they can effectively manage the peak shape of alkaline compounds and provide good selectivity in separating acidic and neutral compounds.The development of various stationary phases has promoted the applications of SFC in numerous fields such as pharmaceuticals, food production, environmental protection, and natural products. In particular, natural products have specific active skeletons, multiple active groups, and excellent biological activity; hence, these materials can provide many new opportunities for the discovery of novel drugs. According to reports, compounds related to natural products account for 80% of all commercial drugs. However, natural products are among the most challenging compounds to separate because of their complex composition and low concentration of active ingredients. Thus, superior chromatographic methods are required to enable the qualitative and quantitative analysis of natural products. Thanks to technological improvements and a good theoretical framework, the benefits of SFC are gradually becoming more apparent, and its use in separating natural products is expanding. Indeed, in the past 50 years, SFC has developed into a widely used and efficient separation technology. This article provides a brief overview of the characteristics, advantages, and development process of SFC; reviews the available SFC stationary phases and their applications in natural products over the last decade; and discusses prospects on the future development of SFC.


Assuntos
Cromatografia com Fluido Supercrítico , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Cromatografia com Fluido Supercrítico/métodos , Solventes/química , Água
6.
Zhonghua Nan Ke Xue ; 29(2): 144-150, 2023 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-37847086

RESUMO

OBJECTIVE: To explore the feasibility of Ion Torrent PGM sequencing in detection of Y chromosome microdeletion. METHODS: We enrolled 87 infertility patients with non-obstructive azoospermia (NOA) in this study and analyzed their routine semen parameters, reproductive hormone levels and chromosomal karyotypes. We detected Y chromosome microdeletion in the patients by Ion Torrent PGM sequencing and multiplex PCR, and compared the detection rates between the two methods. RESULTS: Ion Torrent PGM sequencing achieved a significantly higher detection rate of Y chromosome microdeletion than multiplex PCR (49.4% vs 12.6%, P < 0.05). The cases of AZF deletion detected by Ion Torrent PGM sequencing included all those detected by multiplex PCR, and the deletion sites were completely consistent. In addition, 14 male infertility-related gene mutations were detected in 24 of the 87 patients, with a total positive rate of 27.59%. CONCLUSION: Ion Torrent PGM sequencing can significantly improve the detection rate of Y chromosome microdeletion in infertility patients with NOA, detect a variety of male infertility-related gene mutations, and therefore contribute to the diagnosis of azoospermia.


Assuntos
Azoospermia , Infertilidade Masculina , Oligospermia , Humanos , Masculino , Azoospermia/genética , Azoospermia/diagnóstico , Infertilidade Masculina/genética , Deleção Cromossômica , Aberrações dos Cromossomos Sexuais , Cromossomos Humanos Y/genética , Oligospermia/genética
7.
Environ Sci Technol ; 57(35): 13025-13035, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37608438

RESUMO

Exposure to fine particulate matter (PM < 2.5 µm in diameter [PM2.5]) may accelerate human sperm quality decline, although research on this association is limited. Our objective was to investigate the relationship between exposure to the chemical constituents of PM2.5 air pollution and decreased sperm quality and to further explore the exposure-response relationship. We conducted a multicenter population-based cohort study including 78,952 semen samples from 33,234 donors at 6 provincial human sperm banks (covering central, northern, southern, eastern, and southwestern parts of China) between 2014 and 2020. Daily exposure to PM2.5 chemical composition was estimated using a deep learning model integrating a density ground-based measure network at a 1 km resolution. Linear mixed models with subject- and center-specific intercepts were used to quantify the harmful impacts of PM2.5 constituents on semen quality and explore their exposure-response relationships. Per interquartile range (IQR) increase in PM2.5 exposure levels during spermatogenesis was significantly associated with decreased sperm concentration, progressive motility, and total motility. For PM2.5 constituents, per IQR increment in Cl- (ß: -0.02, 95% CI: [-0.03, -0.00]) and NO3- (ß: -0.05, 95% CI: [-0.08, -0.02]) exposure was negatively associated with sperm count, while NH4+ (ß: -0.03, 95% CI: [-0.06, -0.00]) was significantly linked to decreased progressive motility. These results suggest that exposure to PM2.5 chemical constituents may adversely affect human sperm quality, highlighting the urgent need to reduce PM2.5 exposure.


Assuntos
Análise do Sêmen , Sêmen , Masculino , Humanos , Estudos de Coortes , Contagem de Espermatozoides , Material Particulado
8.
J Hazard Mater ; 460: 132330, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37611389

RESUMO

BACKGROUND: Poor sperm quality is a prevalent cause of male infertility, and the association between gaseous ambient air pollutants exposure and semen quality remains unclear. OBJECTIVES: To examine the relationship between gaseous air pollution exposure with semen quality in a large-scale and multi-center study. METHODS: We analyzed 78,952 samples corresponding to 33,234 study subjects from 2014 to 2020. The high-resolution grid pollution dataset was used to estimate personal exposures to CO, SO2, NO2 and O3 across entire stage of semen formation and three crucial stages. The linear mixed models were performed to evaluate the relationships. RESULTS: The results showed that sperm count was inversely related to SO2 exposure (-0.0070, -0.0128 to -0.0011). Decreased sperm concentration was associated with SO2 (-0.0083, -0.0142 to -0.0024), NO2 (-0.0162, -0.0320 to -0.0005) and O3 (-0.0306, -0.0480 to -0.0133) during 0-90 lag days, respectively. Additionally, we observed significant decline of PR and total motility with SO2 exposure. Similar trends were observed for SO2 and CO exposure during 3 key periods. CONCLUSIONS: Our findings suggest that exposure to gaseous air pollutants may have negative impacts on sperm quality. These findings highlight the importance that critical periods of sperm development should be considered when implementing protective measures.


Assuntos
Poluentes Atmosféricos , Poluentes Ambientais , Humanos , Masculino , Gases , Sêmen , Análise do Sêmen , Dióxido de Nitrogênio/toxicidade , Espermatozoides , Poluentes Atmosféricos/toxicidade
9.
Physiol Mol Biol Plants ; 29(6): 783-790, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37520815

RESUMO

Root systems anchor plants to the substrate in addition to transporting water and nutrients, playing a fundamental role in plant survival. The LAZY1 gene mediates gravity signal transduction and participates in root and shoot development and auxin flow in many plants. In this study, a regulator, LsLAZY1, was identified from Leymus secalinus based on previous transcriptome data. The conserved domain and evolutionary relationship were further analyzed comprehensively. The role of LsLAZY1 in root development was investigated by genetic transformation and associated gravity response and phototropism assay. Subcellular localization showed that LsLAZY1 was localized in the nucleus. LsLAZY1 overexpression in Arabidopsis thaliana (Col-0) increased the length of the primary roots (PRs) and the number of lateral roots (LRs) compared to Col-0. Furthermore, 35S:LsLAZY1 transgenic seedlings affected auxin transport and showed a stronger gravitational and phototropic responses. It also promoted auxin accumulation at the root tips. These results indicated that LsLAZY1 affects root development and auxin transport. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01326-4.

10.
Front Plant Sci ; 14: 1115874, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36818828

RESUMO

The RAV (related to ABI3 and VP1) transcription factors are specific and exist in plants, which contain a B3 DNA binding domain and/or an APETALA2 (AP2) DNA binding domain. RAVs have been extensively studied in plants, and more and more evidences show that RAVs are involved in various aspects of plant growth and development, stress resistance and hormone signal transduction. However, the systematic analysis of RAV family in cucumber is rarely reported. In this study, eight CsRAV genes were identified in cucumber genome and we further comprehensively analyzed their protein physicochemical properties, conserved domains, gene structure and phylogenetic relationships. The synteny analysis and gene duplications of CsRAV genes were also analysed. Cis-element analysis revealed that the CsRAVs promoter contained several elements related to plant hormones and abiotic stress. Expression analysis showed that NaCl and ABA could significantly induce CsRAV genes expression. Subcellular localization revealed that all CsRAVs were localized in the nucleus. In addition, 35S:CsRAV1 transgenic Arabidopsis and cucumber seedlings enhanced NaCl and ABA tolerance, revealing CsRAV1 may be an important regulator of abiotic stress response. In conclusion, comprehensive analysis of CsRAVs would provide certain reference for understanding the evolution and function of the CsRAV genes.

12.
J Cell Physiol ; 237(12): 4477-4486, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36183380

RESUMO

Miro1, a mitochondrial Rho GTPase1, is a kind of mitochondrial outer membrane protein involved in the regulation of mitochondrial anterograde transport and its subcellular distribution. Mitochondria influence reproductive processes of mammals in some aspects. Mitochondria are important for oocyte maturation, fertilization and embryonic development. The purpose of this study was to evaluate whether Miro1 regulates mouse oocyte maturation by altering mitochondrial homeostasis. We showed that Miro1 was expressed in mouse oocyte at different maturation stages. Miro1 mainly distributed in the cytoplasm and around the spindle during oocyte maturation. Small interference RNA-mediated Miro1 depletion caused significantly abnormal distribution of mitochondria and endoplasmic reticulum as well as mitochondrial dysfunction, resulting in severely impaired germinal vesicle breakdown (GVBD) of mouse oocytes. For those oocytes which went through GVBD in the Miro1-depleted group, part of them were inhibited in meiotic prophase I stage with abnormal chromosome arrangement and scattered spindle length. Our results suggest that Miro1 is essential for maintaining the maturation potential of mouse oocyte.


Assuntos
Meiose , Mitocôndrias , Oócitos , Proteínas rho de Ligação ao GTP , Animais , Feminino , Camundongos , Gravidez , Homeostase , Mitocôndrias/fisiologia , Oócitos/fisiologia , Oogênese , Proteínas rho de Ligação ao GTP/fisiologia
13.
ACS Pharmacol Transl Sci ; 5(7): 458-467, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35837136

RESUMO

Osteoarthritis (OA) treatment is a highly unmet medical need. Development of a disease-modifying OA drug (DMOAD) is challenging with no approved drugs on the market. Inhibition of ADATMS-4/5 is a promising OA therapeutics to target cartilage degradation and potentially can reduce joint pain and restore its normal function. Starting from the reported ADAMTS-5 inhibitor GLPG1972, we applied a scaffold hopping strategy to generate a novel isoindoline amide scaffold. Representative compound 18 showed high potency in ADATMS-4/5 inhibition, as well as good selectivity over a panel of other metalloproteases. In addition, compound 18 exhibited excellent druglike properties and showed better pharmacokinetic (PK) profiles than GLPG1972 cross-species. Compound 18 demonstrated dose-dependent efficacy in two in vivo rat osteoarthritis models.

14.
Sci Rep ; 12(1): 8579, 2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35595822

RESUMO

Stimulator of interferon genes (STING) activation induces type I interferons and pro-inflammatory cytokines which stimulate tumor antigen cross presentation and the adaptive immune responses against tumor. The first-generation of STING agonists, cyclic di-nucleotide (CDN), mimicked the endogenous STING ligand cyclic guanosine monophosphate adenosine monophosphate, and displayed limited clinical efficacy. Here we report the discovery of SHR1032, a novel small molecule non-CDN STING agonist. Compared to the clinical CDN STING agonist ADU-S100, SHR1032 has much higher activity in human cells with different STING haplotypes and robustly induces interferon ß (IFNß) production. When dosed intratumorally, SHR1032 induced strong anti-tumor effects in the MC38 murine syngeneic tumor model. Pharmacodynamic studies showed induction of IFNß, tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) in the tumors and, to a lower extent, in the plasma. More importantly, we found SHR1032 directly causes cell death in acute myeloid leukemia (AML) cells. In conclusion, our findings demonstrate that in addition to their established ability to boost anti-tumor immune responses, STING agonists can directly eradicate AML cells, and SHR1032 may present a new and promising therapeutic agent for cancer patients.


Assuntos
Leucemia Mieloide Aguda , Proteínas de Membrana , Animais , Apoptose , Citocinas/metabolismo , Humanos , Imunoterapia , Interferon beta/metabolismo , Leucemia Mieloide Aguda/tratamento farmacológico , Proteínas de Membrana/agonistas , Proteínas de Membrana/metabolismo , Camundongos
15.
Aging (Albany NY) ; 14(7): 3191-3202, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35413689

RESUMO

The developmental potential of oocytes decreases with time after ovulation in vivo or in vitro. Epitalon is a synthetic short peptide made of four amino acids (alanine, glutamic acid, aspartic acid, and glycine), based on a natural peptide called epithalamion extracted from the pineal gland. It is a potent antioxidant, comparable to melatonin, that may confer longevity benefits. The current study aims to test the protective effects of Epitalon on the quality of post-ovulatory aging oocytes. Epitalon at 0.1mM was added to the culture medium, and the quality of oocytes was evaluated at 6h, 12h, and 24h of culture. We found that 0.1mM Epitalon reduced intracellular reactive oxygen species. Epitalon treatment significantly decreased frequency of spindle defects and abnormal distribution of cortical granules during aging for 12h and 24h, while increased mitochondrial membrane potential and DNA copy number of mitochondria, thus decreasing apoptosis of oocytes by 24h of in vitro aging. Our results suggest that Epitalon can delay the aging process of oocytes in vitro via modulating mitochondrial activity and ROS levels.


Assuntos
Oligopeptídeos , Oócitos , Envelhecimento , Animais , Feminino , Camundongos , Oócitos/metabolismo , Ovulação , Espécies Reativas de Oxigênio/metabolismo
16.
J Sep Sci ; 45(5): 1051-1058, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34984820

RESUMO

Ephedrae Herba is one of the most commonly used herbal medicines, and it has been shown that most of the clinical efficacy for cold and asthma is exerted by its alkaloidal components. A simple and sensitive high-performance liquid chromatography method was developed using a perfluorooctyl column for the simultaneous determination of five alkaloids (norephedrine, norpseudoephedrine, ephedrine, pseudoephedrine, and methylephedrine) in Ephedrae Herba. The mobile phase comprising acetonitrile and 15 mM ammonium trifluoroacetate was used to elute the targets in isocratic elution mode. The method was validated for linearity (R2  > 0.999), repeatability, intraday and interday precision, recoveries with trueness (93.87-110.99%), limits of detection (5.35-5.76 µg/mL), and limits of quantification (20 µg/mL). The quantitative results revealed that the developed method was precise and accurate. Then it was successfully applied to determine the difference in the contents of three batches of Ephedrae Herba from three pharmaceutical companies.


Assuntos
Alcaloides , Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/análise , Efedrina/análise , Pseudoefedrina/análise
17.
J Cell Physiol ; 236(7): 5352-5361, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33586215

RESUMO

In vitro culture of follicles is a promising technology to generate large quantities of mature oocytes and it could offer a novel option of assisted reproductive technologies. Here we described a 2-dimensional follicular serum-free culture system with 3-dimensional effect that can make secondary follicles develop into antral follicles (78.52%), generating developmentally mature oocytes in vitro (66.45%). The oocytes in this serum-free system completed the first meiosis; spindle assembly and chromosome congression in most oocytes matured from follicular culture were normal. However, these oocytes showed significantly lower activation and embryonic development rates, and their ability to produce Ca2+ oscillations was also lower in response to parthenogenetic activation, after which a 2-cell embryonic developmental block occurred. Oocytes matured from follicular culture displayed increased abnormal mitochondrial distribution and increased reactive oxygen species levels when compared to in vivo matured oocytes. These data are important for understanding the reasons for reduced developmental potential of oocytes matured from follicular culture, and for further improving the cultivation system.


Assuntos
Técnicas de Maturação in Vitro de Oócitos/métodos , Oócitos , Folículo Ovariano , Animais , Núcleo Celular , Citoplasma , Feminino , Camundongos , Oócitos/fisiologia
18.
Opt Express ; 28(4): 4587-4593, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32121692

RESUMO

This paper presents an InAs/InP quantum dash (QD) C-band passively mode-locked laser (MLL) with a channel spacing of 34.224 GHz. By using this QD-MLL we demonstrate an aggregate 5.376 Tbit/s PAM-4 data transmission capacity both for back-to-back (B2B) and over 25-km of standard single mode fiber (SSMF). This represents the first demonstration of QD-MLL acting as error-free operation at an aggregate data transmission capacity of 5.376 Tbit/s for some filtered individual channels. This finding highlights the viability for InAs/InP QD lasers to be used as a low-cost optical source for data center networks.

19.
Se Pu ; 38(5): 547-553, 2020 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-34213239

RESUMO

A new method based on solid-phase extraction-ultraperformance liquid chromatography (SPE-UPLC) was developed for the determination of five protopanaxadiol ginsenosides in ginseng. The ginsenosides were extracted from ground ginseng samples using water-saturated n-butanol and purified on a hydrophilic solid-phase extraction column. Chromatographic separation was achieved on an ACQUITY UPLC BEH Shield RP18 column (100 mm×2.1 mm, 1.7 µm) by linear gradient elution using an acetonitrile/water mobile phase. Five protopanaxadiol ginsenosides were detected by a photodiode array detector, and they showed a strong positive linear correlation (r2>0.999) in the range of 5-500 µg/mL. In addition, the instrument precision ranged between 0.95% and 2.62% (n=6), with the sample stability between 0.90% and 2.15% (n=8) within 22 h. Intra- and inter-day repeatabilities were 5.35%-6.47% (n=6) and 5.56%-6.34% (n=8), respectively. Sample recoveries and the corresponding relative standard deviations (RSDs) were 87.16%-101.92% and 1.54%-4.01% (n=6), respectively. Hydrophilic chromatography materials were used in SPE, and the extract was directly loaded and purified without pretreatment. Besides, with the use of UPLC, the analysis time was greatly shortened. The developed method is simple and rapid, with high throughput, thus being suitable for the quantitative analysis of the five protopanaxadiol ginsenosides in ginsengs.


Assuntos
Ginsenosídeos , Panax , Sapogeninas/análise , Cromatografia Líquida de Alta Pressão , Ginsenosídeos/análise , Panax/química , Extração em Fase Sólida
20.
Opt Express ; 27(24): 35368-35375, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31878707

RESUMO

We have developed and experimentally demonstrated a novel monolithic InAs/InP quantum-dash dual-wavelength distributed feedback (QD DW-DFB) C-band laser as a compact optical beat source to generate millimeter-wave (MMW) signals. The device uses a common gain medium in a single cavity structure for simultaneous correlated and stable dual-mode lasing in the 1550-nm wavelength range. A record narrow optical linewidth down to 15.83 kHz and average relative intensity noise (RIN) as low as -158.3 dB/Hz from 10 MHz to 20 GHz are experimentally demonstrated for the two optical modes generated by the laser. As a result, the beat note between these two lasing modes generates spectrally pure MMW signals between 46 GHz and 48 GHz. Such an efficient, coherent, and compact optical source is extremely attractive for applications in MMW systems, such as Radar and fiber-wireless integrated fronthaul for 5G and beyond.

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