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Objective: To investigate the genetic subtypes and drug resistance monitoring of newly reported human immunodeficiency virus (HIV) infection/AIDS virus in Anhui Province from 2020 to 2023. Methods: An observational design study was used to collect blood samples from patients diagnosed with HIV/AIDS in the AIDS Prevention and Control Department of Anhui Provincial Center for Disease Control and Prevention from January 2020 to December 2023.The HIV-1 pol gene was amplified by reverse transcription-nested PCR, and the genetic subtypes were identified by phylogenetic tree analysis using MEGA 7.0 software. The mutation sites of drug resistance were analyzed by the online software tool of Stanford University's HIV Drug resistance database. The influencing factors of drug resistance before treatment were analyzed by multivariate logistic analysis. Results: A total of 335 plasma samples were collected, and 332 HIV-1 pol gene sequences were obtained successfully. The main gene subtypes were CRF01-AE, accounting for 35.55% (118/332), followed by CRF07-BC, B and B+C types [29.22% (97/332), 11.74% (39/332), 9.93% (33/332)]. The total drug resistance rate before treatment was 30.12%(32/100), and the drug resistance rate of protease inhibitor (PIs) in HIV-1 was 6.33% (21/332). The drug resistance rate of nucleoside reverse transcriptase inhibitors (NRTI) before treatment was 6.33% (21/332). The drug resistance rate of non-nucleoside reverse transcriptase inhibitors (NNRTI) before treatment was 17.47% (58/332).The comparison of drug resistance rate of different drug types showed statistical significance (χ2=30.435, P<0.05).Among the 100 cases of drug resistance, the main mutation point of HIV-1 protease inhibitor was Q58E (21.00%), and the main mutation point of nucleoside reverse transcriptase inhibitor was M184V/I (6.00%). Non-nucleoside reverse transcriptase inhibitor resistance mutation points mainly K103N (22.00%).There were statistically significant differences in the starting time of antiviral therapy, the number of CD4+T cells at baseline and the drug resistance rate of gene subtypes (the chi-square values are respectively 24.152, 32.516, 11.652, P<0.05).Multivariate logistic analysis showed that the baseline CD4+T cell count was <200/µl, subtype B, subtype B+C, CRF01-AE subtype, CRF55-01B subtype and 01-BC subtype was the influential factor of drug resistance before treatment (the chi-square values are respectively 4.577, 8.202, 4.416, 5.206, 7.603 and 4.804, P<0.05). Conclusion: The newly reported HIV/AIDS population in Anhui Province from 2020 to 2023 has a variety of viral gene subtypes, and NNRTIs are the main types of drug resistance gene mutations before treatment. Attention should be paid to the number of baseline CD4+T cells, the duration of antiviral treatment, and the distribution of gene subtypes to reduce the drug resistance of HIV/AIDS patients before treatment.
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Síndrome de Inmunodeficiencia Adquirida , Farmacorresistencia Viral , Genotipo , VIH-1 , Humanos , Farmacorresistencia Viral/genética , VIH-1/genética , VIH-1/efectos de los fármacos , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Síndrome de Inmunodeficiencia Adquirida/virología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Fármacos Anti-VIH/uso terapéutico , Fármacos Anti-VIH/farmacología , Mutación , China/epidemiologíaRESUMEN
Information about molecular collisions is encoded in the shapes of collision-perturbed molecular resonances. This connection between molecular interactions and line shapes is most clearly seen in simple systems, such as the molecular hydrogen perturbed by a noble gas atom. We study the H2-Ar system by means of highly accurate absorption spectroscopy and ab initio calculations. On the one hand, we use the cavity-ring-down-spectroscopy technique to record the shapes of the S(1) 3-0 line of molecular hydrogen perturbed by argon. On the other hand, we simulate the shapes of this line using ab initio quantum-scattering calculations performed on our accurate H2-Ar potential energy surface (PES). In order to validate the PES and the methodology of quantum-scattering calculations separately from the model of velocity-changing collisions, we measured the spectra in experimental conditions in which the influence of the latter is relatively minor. In these conditions, our theoretical collision-perturbed line shapes reproduce the raw experimental spectra at the percent level. However, the collisional shift, δ0, differs from the experimental value by 20%. Compared to other line-shape parameters, collisional shift displays much higher sensitivity to various technical aspects of the computational methodology. We identify the contributors to this large error and find the inaccuracies of the PES to be the dominant factor. With regard to the quantum scattering methodology, we demonstrate that treating the centrifugal distortion in a simple, approximate manner is sufficient to obtain the percent-level accuracy of collisional spectra.
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Narrow optical resonances of atoms or molecules have immense significance in various precision measurements, such as testing fundamental physics and the generation of primary frequency standards. In these studies, accurate transition centers derived from fitting the measured spectra are demanded, which critically rely on the knowledge of spectral line profiles. Here, we propose a new mechanism of Fano-like resonance induced by distant discrete levels and experimentally verify it with Doppler-free spectroscopy of vibration-rotational transitions of CO_{2}. The observed spectrum has an asymmetric profile and its amplitude increases quadratically with the probe laser power. Our results facilitate a broad range of topics based on narrow transitions.
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The (30012) â (00001) band of 12C16O2 in the 1.6 µm region is used for satellite observation of carbon dioxide in the Earth's atmosphere. Here, we report a Doppler-free spectroscopy study of this band with comb-locked wavelength-modulated cavity-enhanced absorption spectroscopy. Frequencies of 18 transitions with the rotational quantum numbers up to 42 were determined with sub-kHz accuracy, corresponding to a fractional uncertainty at the 10-12 level. With this precision, we revealed an anomalous decrease of the line shift and an increase of the line broadening for the Lamb dips of CO2 in the low-pressure regime compared to values obtained from Doppler-limited spectra at higher pressures.
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Interactions between a molecule and two or more laser fields are of great interest in various studies, but weak and highly overlapping transitions hinder precision measurements. We present the method of comb-locked cavity-assisted double resonance spectroscopy based on narrow-linewidth continuous-wave lasers, which allows for state-selective pumping and probing of molecules. By locking two near-infrared diode lasers to one cavity with a finesse at the order of 105, we measured all three types of double resonances. Carbon monoxide molecules with selected speeds along the laser beam were excited to vibrationally excited states, and absorption spectra with sub-MHz linewidths were observed. Positions of double resonance transitions were determined with an accuracy of 3.7 kHz, which was verified by comparing to Lamb-dip measurements. The present work paves the way to the pump-probe study of highly excited molecules with unprecedented precision.
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Spectroscopy of molecules in the mid-infrared (MIR) region has important applications in various fields, such as astronomical observation, environmental detection, and fundamental physics. However, compared to that in the near-infrared, precision spectroscopy in the MIR is often limited by the light source and has not shown full potential in sensitivity. Here we report a cavity ring-down spectroscopy system using a tunable narrow-linewidth optical parametric oscillator, which fulfills the requirement of high sensitivity and high precision in the MIR region. The Lamb-dip spectrum of the N2O molecule at 2.7 µm was measured as a demonstration of spectroscopy in the MIR with kilohertz accuracy.
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Objective: To determine whether 60 Gy is superior to standard 50 Gy for definitive concurrent chemoradiation(CCRT) in esophageal squamous cell carcinoma (ESCC) using modern radiation technology in a phase â ¢ prospective randomized trial. Methods: From April 2013 to May 2017, 331 patients from 22 hospitals who were pathologically confirmed with stage â ¢A-â £A ESCC were randomized to 60 Gy or 50 Gy with random number table. Total of 305 patients were analyzed, including 152 in 60 Gy group and 153 in 50 Gy group. The median age was 63 years, 242(79.3%) males and 63(20.7%) females. The median length of primary tumor was 5.6 cm. The clinical characteristics between two groups were comparable. All patients were delivered 2 Gy per fraction, 5 fractions per week. Concurrent weekly chemotherapy with docetaxel (25 mg/m(2)) and cisplatin (25 mg/m(2)) and 2 cycles consolidation chemotherapy with docetaxel (70 mg/m(2)) and cisplatin (25 mg/m(2), d1-3) were administrated. The primary endpoint was local/regional progression-free survival (LRPFS). The data were compared with Pearson chi-square test or Fisher's exact test. Results: At a median follow-up of 27.3 months, the disease progression rate was 37.5% (57/152), 43.8% (67/153) in the high and standard-dose group, respectively (χ(2)=1.251, P=0.263). The 1, 2, 3-year LRPFS rate was 75.4%, 56.8%, 52.1% and 74.2%, 58.4%, 50.1%, respectively (HR: 0.95, 95%CI: 0.69-1.31, P=0.761). The 1, 2, 3-year overall survival rate was 84.1%, 64.8%, 54.1% and 85.4%, 62.9%, 54.0%, respectively (HR: 0.98, 95%CI: 0.71-1.38, P=0.927). The 1, 2, 3-year progression-free survival rate was 70.8%, 54.2%, 48.5% and 65.5%, 51.9%, 45.1%, respectively (HR: 0.93, 95%CI: 0.68-1.26, P=0.621). The incidence rates in toxicities between the two groups were similar except for higher rate of severe pneumonitis in high dose group (χ(2)=11.596, P=0.021). Conclusions: The efficacy in disease control is similar between 60 Gy and 50 Gy using modern radiation technology concurrent with chemotherapy for ESCC. The 50 Gy should be recommended as the regular radiation dose with CCRT for ESCC.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Protocolos de Quimioterapia Combinada Antineoplásica , Quimioradioterapia , Cisplatino , Terapia Combinada , Neoplasias Esofágicas/terapia , Carcinoma de Células Escamosas de Esófago/terapia , Femenino , Fluorouracilo , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
Precision spectroscopy of fundamental bands of molecules in the mid-infrared (MIR) region is of great interest in applications of trace detection and testing fundamental physics, where high-power and narrow-linewidth MIR lasers are needed. By using a frequency-stabilized near-infrared laser as a seed of the signal light of a continuous-wave optical parametric oscillator, we established a broadly tunable MIR light source that has an output power of several hundred milliwatts and a linewidth of a few tens of kilohertz. The MIR laser frequency drift was reduced to below 1 kHz by using an optical frequency comb to stabilize the frequency of the 1064 nm pumping laser. The performance of the light source was investigated and tested by measuring the saturated absorption spectroscopy of a few molecular transitions at 3.3 µm.
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Noise-immune cavity enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is extremely sensitive in detecting weak absorption. However, the use of NICE-OHMS for metrology study was also hindered by its sensitivity to influence from various experimental conditions such as the residual amplitude modulation. Here we demonstrate to use NICE-OHMS for precision measurements of Lamb-dip spectra of molecules. After a dedicated investigation of the systematic uncertainties in the NICE-OHMS measurement, the transition frequency of a ro-vibrational line of C2H2 near 789 nm was determined to be 379 639 280 915.3±1.2 kHz (fractional uncertainty 3.2 × 10-12), agreeing well with, but more accurate than, the value determined from previous cavity ring-down spectroscopy measurements. The study indicates the possibility to implement the very sensitive NICE-OHMS method for frequency metrology of molecules, or a molecular clock, in the near-infrared.
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Lasing is reported for ridge-waveguide devices processed from a 40-stage InP-based quantum cascade laser structure grown on a 6-inch silicon substrate with a metamorphic buffer. The structure used in the proof-of-concept experiment had a typical design, including an Al0.78In0.22As/In0.73Ga0.27As strain-balanced composition, with high strain both in quantum wells and barriers relative to InP, and an all-InP waveguide with a total thickness of 8 µm. Devices of size 3 mm x 40 µm, with a high-reflection back facet coating, emitted at 4.35 µm and had a threshold current of approximately 2.2 A at 78 K. Lasing was observed up to 170 K. Compared to earlier demonstrated InP-based quantum cascade lasers monolithically integrated onto GaAs, the same laser structure integrated on silicon had a lower yield and reliability. Surface morphology analysis suggests that both can be significantly improved by reducing strain for the active region layers relative to InP bulk waveguide layers surrounding the laser core.
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Precision spectroscopy of the hydrogen molecule is a test ground of quantum electrodynamics (QED), and it may serve for the determination of fundamental constants. Using a comb-locked cavity ring-down spectrometer, for the first time, we observed the Lamb-dip spectrum of the R(1) line in the overtone of hydrogen deuteride (HD). The line position was determined to be 217 105 182.79±0.03_{stat}±0.08_{syst} MHz (δν/ν=4×10^{-10}), which is the most accurate rovibrational transition ever measured in the ground electronic state of molecular hydrogen. Moreover, from calculations including QED effects up to the order m_{e}α^{6}, we obtained predictions for this R(1) line as well as for the HD dissociation energy, which are less accurate but signaling the importance of the complete treatment of nonadiabatic effects. Provided that the theoretical calculation reaches the same accuracy, the present measurement will lead to a determination of the proton-to-electron mass ratio with a precision of 1.3 parts per billion.
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We present a new method of comb-locked cavity ring-down spectroscopy for the Lamb-dip measurement of molecular ro-vibrational transitions. By locking both the probe laser frequency and a temperature-stabilized high-finesse cavity to an optical frequency comb, we realize saturation spectroscopy of molecules with kilohertz accuracy. The technique is demonstrated by recording the R(9) line in the υ = 3 - 0 overtone band of CO near 1567 nm. The Lamb-dip spectrum of such a weak line (transition rate 0.0075 s-1) is obtained using an input laser power of only 3 mW, and the position is determined to be 191 360 212 770 kHz with an uncertainty of 7 kHz (δν/νâ¼3.5×10-11), which is currently limited by our rubidium clock.
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The infrared absorption spectra of the H2O, HDO, and D2O monomers isolated in solid N2 have been recorded at various temperatures between 4 and 30 K. A study of the absorption features of the ν1, ν2, and ν3 vibrational modes for each monomer shows their optical line shapes to be strongly temperature dependent. For all three modes, a decrease in the absorption amplitude and a proportional broadening of the linewidth was observed with increasing temperature, while the integrated absorbance remained constant. These observations were explained in terms of phonon coupling, by which high frequency intramolecular modes decay by exciting matrix phonons. Fits of the linewidth for the lowest frequency ν2 vibrational mode to the predicted vibrational relaxation rate in a solid medium gave average phonon mode frequencies consistent with the Debye frequency for solid N2.
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The third CH stretching vibration overtone (4ν(CH)) of the acetylene molecule has been a prototype for intra-molecular dynamics studies. Using a sensitive cavity ring-down spectrometer calibrated with precise atomic transitions, the absolute line frequencies of 50 lines of this band have been determined with sub-MHz accuracy, or relatively 2 × 10(-9). The accuracy is also confirmed by the combination differences between the transitions sharing the same upper level. The improved accuracy, two orders of magnitude better than previous studies, allows us to reveal finer ro-vibrational couplings. Fitting of the rotational energies indicates that the J-dependent interactions take place after J > 7. The precise line positions present useful confinements to the models of the intra-molecular interactions of the acetylene molecule.
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The low-lying electronic states of Yb isolated in a solid Ne matrix are characterized through absorption and emission spectroscopy. The absorption spectra of matrix isolated Yb while pumped into its triplet states have been recorded for the first time and the 6s6p (3)P(J) â 5d6s (3)D(1, 2) transition frequencies obtained. Under matrix conditions, the structure of these states is found to be qualitatively the same as in the free atom, but the intersystem crossing rate is observed to be several orders of magnitude greater. A proposed explanation for this is curve crossings between the bound potential energy surface correlated to the 6s6p (1)P(1) state and the potential energy surfaces correlated to the 5d6s (3)D(1, 2) states in isolation. The potentials of the Yb·Ne dimer in its lowest electronic states are computed ab initio and used in a pairwise cluster model to explicitly demonstrate these curve crossings.
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A continuous-wave cavity ring-down spectrometer has been built for precise determination of absolute frequencies of Doppler-broadened absorption lines. Using a thermo-stabilized Fabry-Pérot interferometer and Rb frequency references at the 780 nm and 795 nm, 0.1 - 0.6 MHz absolute frequency accuracy has been achieved in the 775-800 nm region. A water absorption line at 12579 cm(-1) is studied to test the performance of the spectrometer. The line position at zero-pressure limit is determined with an uncertainty of 0.3 MHz (relative accuracy of 0.8 × 10(-9)).
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Interferometría/instrumentación , Análisis Espectral/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Sensibilidad y EspecificidadRESUMEN
A continuous-wave cavity ring-down spectrometer with sub-MHz precision has been built using the sideband of a frequency stabilized laser as the tunable light source. The sideband is produced by passing the carrier laser beam through an electro-optic modulator (EOM) and then selected by a short etalon on resonance. The carrier laser frequency is locked to a longitude mode of a thermo-stabilized Fabry-Perot interferometer (FPI) with a long-term absolute frequency stability of 0.2 MHz (5 × 10(-10)). Broad and precise spectral scanning is accomplished, respectively, by selecting a different longitudinal mode of the FPI and by tuning the radio-frequency driving the EOM. The air broadened water absorption line at 12,321 cm(-1) was studied to test the performance of the spectrometer.
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The Boltzmann constant can be optically determined by measuring the Doppler width of an absorption line of molecules at gas phase. We propose to apply a near infrared cavity ring-down (CRD) spectrometer for this purpose. The superior sensitivity of CRD spectroscopy and the good performance of the near-ir lasers can provide ppm (part-per-million) accuracy which will be competitive to present most accurate result obtained from the speed of sound in argon measurement. The possible influence to the uncertainty of the determined Doppler width from different causes are investigated, which includes the signal-to-noise level, laser frequency stability, detecting nonlinearity, and pressure broadening effect. The analysis shows that the CRD spectroscopy has some remarkable advantages over the direct absorption method proposed before. The design of the experimental setup is presented and the measurement of C2H2 line near 0.8 µm at room temperature has been carried out as a test of the instrument.
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Espectrofotometría/métodos , Espectroscopía Infrarroja Corta/métodos , Acústica , Argón/química , Diseño de Equipo , Gases , Luz , Modelos Estadísticos , Distribución Normal , Óptica y Fotónica/métodos , Oxígeno/química , Presión , Reproducibilidad de los Resultados , TemperaturaRESUMEN
To observe the effects of small interfering RNA (siRNA)-targeting bone morphogenetic protein (BMP)-2 on the abilities of migration and invasion of human liver cancer SMMC7721 cells and its mechanism. Three siRNAs-targeting BMP-2 gene were synthesized. There were six groups including group I (non-transfected cells), group II (only liposome-transfected cells), group III (non-specific siRNA-transfected cells) and groups IV-VI (siRNA-A, siRNA-B and siRNA-C-targeting BMP-2 transfected cells, respectively). SMMC7721 cells were instantaneously transfected using lipofectamine method. The levels of mRNA and protein of BMP-2 in cells were determined with reverse transcription-PCR and western blotting. The abilities of migration and invasion of transfected cells were assessed using scratch test and in vitro invasion assay, respectively. The protein levels of p-ERK, p-JNK and p-p38 and the protein levels of MMP-2 and MMP-9 were evaluated with western blot 48 h after siRNA-B-targeting BMP-2 was transfected into liver cancer SMMC7721 cells. Expression of mRNA and protein of BMP-2 in groups IV-VI were significantly inhibited, especially in group V. Cell scratch width was significantly greater in group V than in group I and III (P<0.01). In vitro invasion assay suggested that the number of invasion of cells was significantly lower in group V than in group I and III (P<0.05). Western blot indicated that the level of p-ERK was significantly decreased (P<0.05), the levels of p-JHK and p-p38 were not significantly changed and the levels of MMP-2 and MMP-9 were significantly downregulated (P<0.05). siRNA-targeting BMP-2 can markedly inhibited the expression of BMP-2 in liver cancer SMMC7721 cells, and decrease the abilities of migration and invasion of liver cancer cells, especially siRNA-B. The inhibitory effects of siRNA-B-targeting BMP-2 on the abilities of migration and invasion of human liver cancer SMMC7721 cells may be caused by the downregulation of MMP-2 and MMP-9 through MAPK/ERK pathway, whereas is not related to MAPK/JNK and MAPK/p38 pathway.
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Proteína Morfogenética Ósea 2/metabolismo , Movimiento Celular/fisiología , ARN Interferente Pequeño/genética , Western Blotting , Proteína Morfogenética Ósea 2/genética , Línea Celular Tumoral , Movimiento Celular/genética , Humanos , Neoplasias Hepáticas/genética , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , ARN Interferente Pequeño/fisiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/genética , Transducción de Señal/fisiologíaRESUMEN
We report a magneto-optical trap of metastable krypton atoms with a trap loading rate of 3×10(11) atoms/s and a trap capture efficiency of 3×10(-5). The system starts with an atomic beam of metastable krypton produced in a liquid-nitrogen cooled, radio-frequency driven discharge. The metastable beam flux emerging from the discharge is 1.5×10(14) atoms/s/sr. The flux in the forward direction is enhanced by a factor of 156 with transverse laser cooling. The atoms are then slowed inside a Zeeman slower before captured by a magneto-optic trap. The trap efficiency can be further improved, possibly to the 10(-2) level, by gas recirculation. Such an atom trap is useful in trace analysis applications where available sample size is limited.