Perioperative Administration of Tranexamic Acid and Low Molecular Weight Heparin for Enhanced Blood Management in Intertrochanteric Fractures: A Randomized Controlled Study.

BACKGROUND This prospective study from a single center aimed to compare the perioperative blood loss (PBL) in 79 patients with intertrochanteric fractures (IF) treated with intramedullary nailing (IMN) using 3 regimens of combined tranexamic acid (TXA) and low molecular weight heparin (LMWH), proposing a novel therapy of 4-dose TXA. MATERIAL AND METHODS We recruited 79 patients and randomly divided them into 3 groups. The 4-dose TXA group (22 patients) received 1.0 g intravenous TXA 30 min before surgery and 1.0 g at intervals of 3, 6, and 9 h before surgery. The 1-dose TXA group (25 patients) received 1.0 g intravenous TXA 30 min before surgery, while the control group (32 patients) did not receive TXA. LMWH was applied 12 h after surgery in each group. The primary metrics evaluated included hidden blood loss (HBL), total blood loss (TBL), and the number and incidence rate of deep vein thrombosis (DVT). RESULTS Analysis of the HBL revealed that the 4-dose TXA group had the lowest average (583.13±318.08 ml), followed by the 1-dose TXA group (902.94±509.99 ml), and the control group showed the highest (1154.39±452.06 ml) (P<0.05). A similar result was observed for TBL (4-dose group: 640.86±337.22 ml, 1-dose group: 971.74±511.14 ml, control group: 1226.27±458.22 ml, P<0.05). Regarding DVT, the 4-dose TXA group had 5 cases (incidence rate 22.73%), the 1-dose TXA group had 6 cases (incidence rate 24.00%), and the control group had 8 cases (incidence rate 25.00%), with no significant difference among groups (P>0.05). CONCLUSIONS Treatment using 4-dose TXA and LMWH can effectively reduce PBL without increasing the DVT risk in IF patients with IMN.

Self-absorption correction method based on intensity self-calibration of doublet lines.

The self-absorption effect in an optically thick plasma seriously affects the spectral line intensity and the measurement accuracy of laser-induced breakdown spectroscopy (LIBS). In this work, a self-absorption correction method based on intensity self-calibration of doublet lines belonging to the same multiplet is proposed. The K/Δλ0 parameter and self-absorption coefficient (SA) of the doublet lines of the analytical element can be calculated based on the measured actual lines intensity ratio and the K parameters ratio. Compared with the generally applied self-absorption correction methods, this method can effectively reduce the influence of laser energy and plasma plume fluctuations and the non-uniformity distribution of the element in the plasma, and is independent of the availability of Stark broadening coefficients. So it has obvious advantages of high computation efficiency, high analysis accuracy and good applicability. Univariate quantitative analysis results of aluminum (Al) show that the correlation coefficient of calibration curves and the measurement accuracy of elemental content have been significantly improved with the self-absorption correction.

150 Gbps multi-wavelength FSO transmission with 25-GHz ITU-T grid in the mid-infrared region.

The 3∼5 µm mid-infrared (mid-IR) light has several exceptional benefits in the case of adverse atmospheric conditions compared to the 1.5 µm band, so it is a promising candidate for optical carriers for free-space communication (FSO) through atmospheric channels. However, the transmission capacity in the mid-IR band is constrained in the lower range due to the immaturity of its devices. In this work, to replicate the 1.5 µm band dense wavelength division multiplexing (DWDM) technology to the 3 µm band for high-capacity transmission, we demonstrate a 12-channel 150 Gbps FSO transmission in the 3 µm band based on our developed mid-IR transmitter and receiver modules. These modules enable wavelength conversion between the 1.5 µm and 3 µm bands based on the effect of difference-frequency generation (DFG). The mid-IR transmitter effectively generates up to 12 optical channels ranging from 3.5768 µm to 3.5885 µm with a power of 6.6 dBm, and each channel carries 12.5 Gbps binary phase shift keying (BPSK) modulated data. The mid-IR receiver regenerates the 1.5 µm band DWDM signal with a power of -32.1 dBm. Relevant results of regenerated signal demodulation have been collected in detail, including bit error ratio (BER), constellation diagram, and eye diagram. The power penalties of the 6th to 8th channels selected from the regenerated signal are lower than 2.2 dB compared with back-to-back (BTB) DWDM signal at a bit error ratio (BER) of 1E-6, and other channels can also achieve good transmission quality. It is expected to further push the data capacity to the terabit-per-second level by adding more 1.5 µm band laser sources and using wider-bandwidth chirped nonlinear crystals.

High average power amplification of femtosecond pulses based on the Yb:CaYAlO4 crystal.

In this paper, we demonstrated the direct amplification of femtosecond pulses with the Yb:CaYAlO4 crystal for the first time. A compact and simple two-stage amplifier delivered amplified pulses with the average powers of 55.4 W for σ-polarization and 39.4 W for π-polarization at the center wavelengthes of 1032 nm and 1030 nm, corresponding to 28.3% and 16.3% optical-to-optical efficiencies, respectively. These are to the best of our knowledge the highest value achieved with a Yb:CaYAlO4 amplifier. Upon using a compressor consisting of prisms and GTI mirrors, a pulse duration of 166-fs was measured. Thanks to the good thermal management, the beam quality (M2) parameters <1.3 along each axis were maintained in each stage.

Free-space transmission of picosecond-level, high-speed optical pulse streams in the 3†µm band.

The utilization of mid-infrared (mid-IR) light spanning the 3-5 µm range presents notable merits over the 1.5 µm band when operating in adverse atmospheric conditions. Consequently, it emerges as a promising prospect for serving as optical carriers in free-space communication (FSO) through atmospheric channels. However, due to the insufficient performance level of devices in the mid-IR band, the capability of mid-IR communication is hindered in terms of transmission capacity and signal format. In this study, we conduct experimental investigations on the transmission of time-domain multiplexed ultra-short optical pulse streams, with a pulse width of 1.8 ps and a data rate of up to 40 Gbps at 3.6 µm, based on the difference frequency generation (DFG) effect. The mid-IR transmitter realizes an effective wavelength conversion of optical time division multiplexing (OTDM) signals from 1.5 µm to 3.6 µm, and the obtained power of the 40 Gbps mid-IR OTDM signal at the optimum temperature of 54.8 °C is 7.4 dBm. The mid-IR receiver successfully achieves the regeneration of the 40 Gbps 1.5 µm OTDM signal, and the corresponding regenerated power at the optimum temperature of 51.5 °C is -30.56 dBm. Detailed results pertaining to the demodulation of regeneration 1.5 µm OTDM signal have been acquired, encompassing parameters such as pulse waveform diagram, bit error rate (BER), and Q factor. The estimated power penalty of the 40 Gbps mid-IR OTDM transmission is 2.4 dB at a BER of 1E-6, compared with the back-to-back (BTB) transmission. Moreover, it is feasible by using chirped PPLN crystals with wider bandwidth to increase the data rate to the order of one hundred gigabits.

High-flux wavelength tunable XUV source in the 12-40.8†eV photon energy range with adjustable energy and time resolution for Tr-ARPES applications.

High-order harmonic generation (HHG) has a broad spectrum covering vacuum ultraviolet to extreme ultraviolet (XUV) bands, which is useful for applications involving material analyses at different information depths. Such an HHG light source is perfect for time- and angle-resolved photoemission spectroscopy. Here, we demonstrate a high-photon flux HHG source driven by a two-color field. Applying a fused silica compression stage to reduce the driving pulse width, we obtained a high XUV photon flux of 2 × 1012 phs/s @21.6 eV on target. We designed a classical diffraction mounted (CDM) grating monochromator that can achieve a wide range of photon energy from 12 to 40.8 eV, while the time resolution is improved by reducing the pulse front tilt after the harmonic selection. We designed a spatial filtering method to adjust the time resolution using the CDM monochromator and significantly reduced the pulse front tilt of the XUV pulses. We also demonstrate a detailed prediction of the energy resolution broadening which is caused by the space charge effect.

Kerr-lens mode-locked femtosecond Yb:CALYO oscillator with more than 20-W average power.

We report on the demonstration of a pure Kerr-lens mode-locked Yb:CALYO laser which can directly deliver sub-200 fs pulses with more than 20-W average power. With an incident pump power of 89 W, 153-fs pulses were generated with an average power of 21.5 W at a repetition rate of 77.9 MHz. The corresponding peak power and single pulse energy were 1.6 MW and 0.27 µJ, respectively. The stable operation of the mode-locking was confirmed by very small fluctuations in both spectrum and output power recorded over an hour. Second harmonic generation (SHG) was conducted with 59% conversion efficiency, which indicated that the high-power mode-locking pulses are of good quality. Stable Kerr-lens mode-locking (KLM) with 156-fs pulse duration and 27.2-W average power was also achieved with 109-W pump power. To the best of our knowledge, this is the highest average output power ever reported from a femtosecond mode-locked bulk oscillator.

Decursin alleviates LPS-induced lung epithelial cell injury by inhibiting NF-κB pathway activation.

OBJECTIVE: To reveal the possible effects of decursin on viability, oxidative stress, and inflammatory response in lipopolysaccharide (LPS)-treated human bronchial epithelial cells-2B (BEAS-2B) and human pulmonary artery endothelial cells (HPAEC) cells, and revealed the potential mechanisms. METHODS: LPS was used to induce acute lung injury (ALI) in normal human lung epithelial cells, including BEAS-2B and HPAEC cells. Cell viability and apoptosis in response to LPS and decursin in BEAS-2B and HPAEC cells were, respectively, evaluated by MTT colorimetric and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays. The oxidative stress and inflammatory response in LPS-treated BEAS-2B and HPAEC cells were detected by enzyme-linked-immunosorbent serologic assay. In addition, the role of decursin in nuclear -factor-kappa B (NF-κB) activation was analyzed by immunoblot and immunofluorescence assays. RESULTS: Our data revealed that decursin could alleviate the viability of LPS-induced BEAS-2B and HPAEC cells. Decursin could also reduce LPS-induced oxidative stress in BEAS-2B and HPAEC cells. In addition, it could reduce LPS-induced inflammation in BEAS-2B and HPAEC cells. Mechanically, decursin suppressed the activation of NF-κB pathway. CONCLUSION: Decursin suppressed NF-κB pathway, and therefore alleviated ALI.

High energy widely tunable narrow-linewidth Ti:sapphire laser using combined-cavity configuration.

A high-energy narrow-linewidth Ti:sapphire laser with widely tunable wavelength was investigated. The Littman cavity was seeded by an extended prism cavity, and they were coupled together by sharing a partial reflection mirror. The widely wavelength tunability of the prism cavity and the linewidth compression of Littman cavity were incorporated together, which resulted in a significantly increased tunable wavelength range from 720 nm to 884 nm with linewidth of less than 100 MHz. The coupling effect and the synchronization between the two cavities in temporal and spectral domain were discussed. The narrow-linewidth laser centered at 786 nm was further amplified to 36 mJ and frequency-doubled to 393 nm with pulse energy of 18.8 mJ while maintaining the narrow linewidth at a repetition rate of 10 Hz. This widely tunable narrow-linewidth laser is a promising light source for high-resolution fluorescence spectroscopy.

Power-scalable thin-disk Ti:sapphire laser amplifier.

We experimentally demonstrate a 38-fs chirped-pulse amplified (CPA) Ti:sapphire laser system based on the power-scalable thin-disk scheme with an average output power of 1.45 W at a repetition rate of 1 kHz, corresponding to peak power of 38 GW. The beam profile close to the diffraction limit with a measured M2 value of approximately 1.1 is obtained. It demonstrates the potential for an ultra-intense laser with high beam quality compared with the conventional bulk gain amplifier. To the best of our knowledge, this is the first reported Ti:sapphire regenerative amplifier based on the thin-disk approach reaching 1 kHz.

Electrolyte Analysis in Blood Serum by Laser-Induced Breakdown Spectroscopy Using a Portable Laser.

The fast and reliable analysis of electrolytes such as K, Na, Ca in human blood serum has become an indispensable tool for diagnosing and preventing diseases. Laser-induced breakdown spectroscopy (LIBS) has been demonstrated as a powerful analytical technique on elements. To apply LIBS to the quantitative analysis of electrolyte elements in real time, a self-developed portable laser was used to measure blood serum samples supported by glass slides and filter paper in this work. The partial least squares regression (PLSR) method was employed for predicting the concentrations of K, Na, Ca from serum LIBS spectra. Great prediction accuracies with excellent linearity were obtained for the serum samples, both on glass slides and filter paper. For blood serum on glass slides, the prediction accuracies for K, Na, Ca were 1.45%, 0.61% and 3.80%. Moreover, for blood serum on filter paper, the corresponding prediction accuracies were 7.47%, 1.56% and 0.52%. The results show that LIBS using a portable laser with the assistance of PLSR can be used for accurate quantitative analysis of elements in blood serum in real time. This work reveals that the handheld LIBS instruments will be an excellent tool for real-time clinical practice.

Generation of annular femtosecond few-cycle pulses by self-compression and spatial filtering in solid thin plates.

Annular-shaped femtosecond few-cycle pulses are generated by 40fs laser pulses propagating through 6 solid thin plates in numerical simulations as well as in experiments. The generation of such pulses takes advantage of the conical emission caused by plasma effect, which introduces continuously varying off-axis plasma density along the radial direction of the propagating beam. The negative dispersion induced by the plasma causes the pulse at particular radial location to be self-compressed and to form an annular beam of short pulse, which can be extracted simply by spatial filtering. Meanwhile, by adjusting the input pulse energy and position of each thin plate relative to the laser focus, we control the plasma density in thin plates which changes the ratio between ionization and effects providing positive dispersion, and obtain a higher compression ratio indicating that the scheme of solid thin plates has the flexibility to regulate the laser intensity so as to plasma density, thus the negative dispersion the pulse experiences during propagation. Few-cycle pulses as short as 8.8 fs are generated in experiments, meanwhile the shortest pulse duration found in the simulations is 5.0 fs, which corresponds to two optical cycles at its central wavelength 761 nm. This method has great potential in high-power few-cycle pulse generation.

2-GHz watt-level Kerr-lens mode-locked Yb:KGW laser.

We report on a 2-GHz high-power Kerr-lens mode-locked Yb:KGW laser pumped by a single-mode fiber laser. The output performance for two different output coupling rates was investigated. Stable bidirectional mode-locking operation at the repetition rate of 2.157 GHz was obtained with a 0.6% output coupler. The average output powers of bidirectional operation are 741 mW and 746 mW, with 123-fs and 126-fs pulse durations, respectively. By using a 1.6% output coupler, unidirectional mode-locking is achieved with 145-fs pulse duration and 1.7-W average output power, which, to the best of our knowledge, is the highest average power from Kerr-lens mode-locked GHz femtosecond oscillators.

10-W-scale Kerr-lens mode-locked Yb:CALYO laser with sub-100-fs pulses.

We reported a high-power pure Kerr-lens mode-locked Yb:CALYO laser based on the dual-confocal cavity delivering sub-100-fs pulses. The output pulses at 81 MHz have an average power of 10.4 W and the pulse duration of 98 fs, corresponding to the peak power of 1.14 MW. This is, to the best of our knowledge, the highest average power ever reported for a Kerr-lens mode-locked Yb-bulk oscillator. Analysis of the dual-confocal cavity was also conducted, which indicates a way to achieve higher average power. We believe the result described in this Letter may pave a way to develop Kerr-lens mode-locked bulk lasers with much higher average power.

Ultrahigh Resolution Thickness Measurement Technique Based on a Hollow Core Optical Fiber Structure.

An ultrahigh resolution thickness measurement sensor was proposed based on a single mode-hollow core-single mode (SMF-HCF-SMF) fiber structure by coating a thin layer of material on the HCF surface. Theoretical analysis shows that the SMF-HCF-SMF fiber structure can measure coating thickness down to sub-nanometers. An experimental study was carried out by coating a thin layer of graphene oxide (GO) on the HCF surface of the fabricated SMF-HCF-SMF fiber structure. The experimental results show that the fiber sensor structure can detect a thin layer with a thickness down to 0.21 nanometers, which agrees well with the simulation results. The proposed sensing technology has the advantages of simple configuration, ease of fabrication, low cost, high resolution, and good repeatability, which offer great potential for practical thickness measurement applications.

Aspects of the reproductive biology of two pelagic sharks in the eastern Atlantic Ocean.

This study used data provided by the Chinese Longline Fishery Scientific Observer Programme from the tropical eastern Atlantic Ocean to estimate the reproductive parameters of the blue shark (Prionace glauca) and crocodile shark (Pseudocarcharias kamoharai). Sizes ranged from 80 to 298 cm fork length (FL) for blue sharks and from 48 to 99 cm FL for crocodile sharks. Sexual segregation was observed during different months for both sharks. The sex ratio for blue sharks was 1.38 F:1 M, and 1 F:2.79 M for crocodile sharks. The size of adult blue sharks ranged from 144 to 280 cm for males and from 174 to 298 cm for females; and that of crocodile sharks from 63 to 97 cm for males and 78-99 cm for females. The size at 50% of maturity for blue sharks was estimated at 191.7 cm FL for females and 197.5 cm FL for males, and that of crocodile sharks was assessed at 84.9 cm FL for females and 78.5 cm FL for males. Most sexually matured females were pregnant; their means were 207.2 ± 16.4 cm FL for blue sharks and 89.4 ± 4.3 cm FL for crocodile sharks. Mature sizes for both species were significantly different among months. Embryonic sizes also varied widely among months for crocodile sharks, but a slight change was recorded for those of blue sharks. The observed mean size at birth and litter size were 34.5 cm FL and 37 ± 12 for the blue sharks, and that of the crocodile sharks, 39.5 cm FL and a dominant four embryos in the uterus. Due to the observed increasing catch trend of blue sharks and the slow reproductive cycle of crocodile sharks, this study presents the need of implementing conservation measures to ensure the sustainability of both species in their habitat.

Diode-pumped high-power sub-100 fs Kerr-lens mode-locked Yb:CaYAlO4 laser with 1.85 MW peak power.

We demonstrated a diode-pumped high-power Kerr-lens mode-locked Yb:CaYAlO4 (Yb:CALYO) laser with a dual-confocal cavity, directly generating 59-fs pulses with 6.2 W average power, which is the highest average power from any sub-60 fs Yb-doped solid-state lasers. With the repetition rate of 50 MHz, the corresponding single pulse energy was 124 nJ and the peak power was 1.85 MW, which to the best of our knowledge is the highest peak power delivered directly from a sub-100 fs Yb-based bulk lasers ever.

High power sub 100-fs Kerr-lens mode-locked Yb:YSO laser pumped by single-mode fiber laser.

We report on a Kerr-lens mode-locked Yb:YSO lasers for the first time. Pumped by a single-mode fiber laser with high brightness and linear polarization, the Yb:YSO laser can deliver as high as 2 W average power with as short as 95 fs pulse duration at the repetition rate of 137.2 MHz, resulting in the single pulse energy of 14.8 nJ and the peak power of 155.7 kW. This work proves the potential on generation of sub-100 fs pulses with multi-watt level average power with the Yb doped oxyorthosilicates crystals.

Highly-stable mode-locked PM Yb-fiber laser with 10 nJ in 93-fs at 6 MHz using NALM.

We demonstrate highly stable mode-locked Yb-doped fiber oscillators using a nonlinear amplifying loop mirror, delivering linearly polarized laser pulses with high energy at a low repetition rate of several MHz. These lasers are composed of polarization-maintaining fibers and fiber-based components without intra-cavity dispersion compensation. The spectral and temporal characteristics are systematically investigated at different repetition rates. Spectral bandwidth of 31 nm is realized in the case of 6 MHz repetition rate, and the pulse energy reaches 10 nJ. A pair of gratings compresses the output pulse to 93 fs. RMS power stability is as low as 0.04% in 10 hours, which shows excellent stability. We believe that this type of fiber oscillator is an ideal seed for further high power amplification.

Harmonically pumped femtosecond optical parametric oscillator with multi-gigahertz repetition rate.

We report a multi-gigahertz (GHz) repetition-rate femtosecond MgO:PPLN optical parametric oscillator (OPO) harmonically pumped by a 75.6 MHz Kerr-lens mode-locked Yb:KGW laser. By fractionally increasing the OPO cavity length, we obtained OPO operation up to the 493rd harmonic of the pump laser repetition rate, corresponding to a repetition rate as high as 37.3 GHz. Using a 1.5% output coupler, we are able to extract signal pulses with up to 260 mW average power at the 102nd harmonic (7.7 GHz) and 90 mW at the 493rd harmonic (37.3 GHz) under 2 W pump power. The measured relative standard deviations of the fundamental and the 102nd harmonic signal power were recorded to be 0.5% and 2.1%, respectively. The signal pulse durations at different harmonics were measured in the range of 160-230 fs.