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•Acidic ILs catalyzed lignocellulose conversion to LA selectively and recyclably.•The highest yield of LA was 96.6mol% under hydrothermal conditions.•Catalytic activity of IL depends ...on anion, including acidity and H-bonding ability.•IL can be reused over 5 cycles without loss of activity.•The lignin fraction sustains the scaffold structure without modifications.
Acidic ionic liquid (IL) C3SO3HmimHSO4 was applied to catalyze lignocellulose conversion to levulinic acid (LA) in one pot with high selectivity under hydrothermal conditions. Through the optimization of reaction conditions, the highest yield of LA is 96.6mol% (21.6wt%) based on the amount of C6-sugars in the straw. The relationship between IL structure and LA yield was established, disclosing that acidity and hydrogen bonding ability of anions are crucial to the yield of LA. Moreover, the LA product can be readily separated through extraction by methyl isobutyl ketone (MIBK) and IL can be reused over 5 cycles without loss of activity. In addition, the chemical structures and morphologies of the solid residues were investigated by DTG, SEM and IR, demonstrating the gradual conversion process of cellulose and hemicellulose accompanied by the formation of humin byproducts, whereas the lignin fraction of the straw sustains the scaffold structure without modifications during the reaction.
Regulation of hematopoietic stem cells (HSCs) by bone marrow (BM) niches has been extensively studied; however, whether and how HSC subpopulations are distinctively regulated by BM niches remain ...unclear. Here, we functionally distinguished reserve HSCs (rHSCs) from primed HSCs (pHSCs) based on their response to chemotherapy and examined how they are dichotomously regulated by BM niches. Both pHSCs and rHSCs supported long-term hematopoiesis in homeostasis; however, pHSCs were sensitive but rHSCs were resistant to chemotherapy. Surviving rHSCs restored the HSC pool and supported hematopoietic regeneration after chemotherapy. The rHSCs were preferentially maintained in the endosteal region that enriches N-cadherin+ (N-cad+) bone-lining cells in homeostasis and post-chemotherapy. N-cad+ cells were functional bone and marrow stromal progenitor cells (BMSPCs), giving rise to osteoblasts, adipocytes, and chondrocytes in vitro and in vivo. Finally, ablation of N-cad+ niche cells or deletion of SCF from N-cad+ niche cells impaired rHSC maintenance during homeostasis and regeneration.
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•rHSC and pHSCs are distinguished by their resistance or sensitivity to chemotherapy•pHSCs in the perivascular niche are largely eliminated by chemotherapy•rHSCs are maintained by N-cad+ cells and restore the HSC pool after chemotherapy•N-cad+ BMSPCs expand and produce SCF and other cytokines for rHSCs upon stress
Zhao et al. demonstrate that blood-forming stem cells have a back-up system in stressed condition. Both reserve and active stem cells are maintained in the bone marrow by specific niches. While the latter are chemo-sensitive, the former survive and restore stem cells, and thereby generate the blood system.
The mammalian imprinted Dlk1-Gtl2 locus produces multiple non-coding RNAs (ncRNAs) from the maternally inherited allele, including the largest miRNA cluster in the mammalian genome. This locus has ...characterized functions in some types of stem cell, but its role in hematopoietic stem cells (HSCs) is unknown. Here, we show that the Dlk1-Gtl2 locus plays a critical role in preserving long-term repopulating HSCs (LT-HSCs). Through transcriptome profiling in 17 hematopoietic cell types, we found that ncRNAs expressed from the Dlk1-Gtl2 locus are predominantly enriched in fetal liver HSCs and the adult LT-HSC population and sustain long-term HSC functionality. Mechanistically, the miRNA mega-cluster within the Dlk1-Gtl2 locus suppresses the entire PI3K-mTOR pathway. This regulation in turn inhibits mitochondrial biogenesis and metabolic activity and protects LT-HSCs from excessive reactive oxygen species (ROS) production. Our data therefore show that the imprinted Dlk1-Gtl2 locus preserves LT-HSC function by restricting mitochondrial metabolism.
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•Transcriptome profiling reveals Gtl2-derived ncRNA enrichment in LT-HSCs•Loss of Dlk1-Gtl2 imprinting leads to functional defects in fetal liver HSCs•miRNAs of the Dlk1-Gtl2 locus suppress components of the entire PI3K-mTOR pathway•PI3K-mTOR inhibition restricts mitochondrial metabolism to preserve LT-HSC function
Qian and colleagues show that ncRNAs expressed from the imprinted locus Dlk1-Gtl2 maintain fetal liver and adult LT-HSCs through multiplexed inhibition of PI3K-mTOR signaling that in turn keeps mitochondrial biogenesis and metabolic activity in check.
Novel bamboo activated carbon (BAC) catalysts decorated with manganese oxides (MnOx) were prepared with varying MnOx contents through a facile one-step redox reaction. Due to the physical anchoring ...effect of the natural macropore structure for catalyst active components, homogeneous MnOx nanoparticles (NPs), and high specific surface area over catalyst surface, the BAC@MnOx-N (N = 1, 2, 3, 4, 5) catalyst shows encouraging adsorption and catalytic oxidation for indoor formaldehyde (HCHO) removal at room temperature. Dynamic adsorption and catalytic activity experiments were conducted. The higher Smicro (733 m2/g) and Vmicro/Vt (82.6%) of the BAC@MnOx-4 catalyst could facilitate its excellent saturated and breakthrough adsorption capacity (5.24 ± 0.42 mg/g, 2.43 ± 0.22 mg/g). The best performer against 2 ppm HCHO is BAC@MnOx-4 catalyst, exhibiting a maximum HCHO removal efficiency of 97% for 17 h without any deactivation as RH = 0, which is higher than those of other MnOx-based catalysts. The average oxidation state and in situ DRIFTS analysis reveal that abundant oxygen vacancies on the BAC@MnOx-4 catalyst could be identified as surface-active sites of decomposing HCHO into the intermediate species (dioxymethylene and formate). This study provides a potential approach to deposit MnOx nanoparticles onto the BAC surface, and this hybrid BAC@MnOx material is promising for indoor HCHO removal at room temperature.
Strength training is recommended by the American Physical Therapy Association to improve muscle strength, mobility, and balance following knee replacement. Few studies have focused on the direct ...effects of strength training on functional ambulation, and potential dose-response relationships between strength training parameters and the effect remain unclear. The aim of this systematic review, meta-analysis, and meta-regression was to evaluate the effects of strength training on functional ambulation following knee replacement (KR). We also aimed to explore potential dose-response relationships between strength training parameters and performance in functional ambulation. A systematic literature search of eight online databases was performed on March 12, 2023, for randomized controlled trials evaluating the effects of strength training on functional ambulation by six-minute walk test (6MWT) or timed-up and go test (TUG) after KR. Data were pooled by random-effect meta-analyses and presented as weighted mean difference (WMD). A random-effect meta-regression was performed for four predetermined training parameters, namely, duration (weeks), frequency (sessions per week), volume (time per session), and initial time (after surgery) separately to explore dose-response relationships with WMD. Fourteen trials encompassing 956 participants were included in our study. Meta-analyses showed an improvement in 6MWT performance after strength training (WMD: 32.15, 95% CI 19.44-44.85) and a decrease in time to complete TUG (WMD: - 1.92, 95% CI - 3.43 to - 0.41). Meta-regression revealed a dose-response relationship only between volume and 6MWT, with a decreasing trend (P = 0.019, 95% CI - 1.63 to - 0.20). Increasing trends of improvement in 6MWT and TUG were observed with increasing training duration and frequency. A slight decreasing trend of improvement was observed in 6MWT with postponed initial time, while an opposite trend was observed in TUG. Based on existing studies, moderate-certainty evidence suggests that strength training could increase 6MWT distance, and low-certainty evidence shows that strength training could decrease the time to complete TUG after KR. Meta-regression results only suggested a dose-response relationship between volume and 6MWT with a decreasing trend.Registration: PROSPERO: CRD42022329006.
Background. The number of patients with musculoskeletal pain, which seriously affects people’s quality of life, has increased. Traditional Chinese exercises are accepted and practiced to strengthen ...the body. Objective. This study aims to explore the efficacy of traditional Chinese exercises for the treatment of musculoskeletal pain. Methods. A comprehensive search of randomized controlled trials (RCTs) related to traditional Chinese exercises on patients with musculoskeletal pain was completed using PubMed, SinoMed, CNKI, VIP, and Wanfang Med Online databases. All RCTs published until February 2021 were considered. Two researchers independently screened the literature according to the predesigned inclusion and exclusion criteria, and data was extracted and assessed for their risk of bias via the Cochrane collaboration tool. Meta-analysis was performed using RevMan5.2 and Rx64 4.0.2 software. Results. A total of 45 RCT studies with 3178 patients were included. Traditional Chinese exercises were able to effectively alleviate patients with musculoskeletal pain (MD = −1.54, 95% confidence interval (−1.88, −1.19), P < 0.01). Among them, the Yi Jin Jing exercise was superior to other exercises, while Wu Qin Xi showed no significant effects. Besides, traditional Chinese exercises had significant positive effects on the dysfunction and stiffness of the waist and knee joints. Traditional Chinese exercises could effectively relieve the clinical symptoms of patients with musculoskeletal pain. Particularly, the Yi Jin Jing exercise presented the most significant positive effect on pain reduction.
The objective of this study is to investigate the impacts of steam heat treatment parameters (e.g., temperature, time, and pressure) on the impact toughness of rattan (Calamus simplicifolius). The ...Box–Behnken design response surface analysis was employed to optimize the steam heat treatment parameters. Impact toughness was selected as the evaluation index, with single-factor tests conducted as a baseline for comparison. Changes in chemical composition, cellulose crystallinity, and pyrolysis properties were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, Thermogravimetry–Fourier transform infrared (TG-FTIR) spectra, and wet-chemistry methods for both untreated control samples and the heat-treated samples. The results show that a 1 h steam heat treatment at 160 °C under 0.1 MPa pressure has the optimal process parameters for the rattan. The achieved impact toughness value closely matches the predicted value at 71.29 kJ/m2. After the steam heat treatment, hemicellulose and cellulose contents decrease, whereas relative lignin content increases significantly, leading to improved toughness characteristics in Calamus simplicifolius samples. The TG results indicate that maximum weight loss occurs at temperatures of 352 °C, 354 °C, and 361 °C, respectively, for three different samples. This suggests that the thermal stability is enhanced as a result of the heat treatment. These findings will help optimize the heat treatments of the rattan material.
This study investigated the effects of bamboo age, bamboo parts, and pyrolysis temperatures on the physiochemical properties of bamboo char throughout a series of pyrolysis processes spanning from ...150 °C to 1000 °C. The results indicated that as the pyrolysis temperature increased from 150 °C to 500 °C, the yield of bamboo char experienced a rapid decline, settling at a maximum of 69%, with no significant impact from bamboo age and parts. Subsequently, as the pyrolysis temperature continued to rise from 500 °C to 1000 °C, the yield stabilized at 25.74–32.64%. Besides, fixed carbon (FC), volatile matter (VM), and ash content were temperature-dependent, while the H/C, O/C, (N + O)/C, and aromatic index kept constant after reaching 500 °C. Notably, 800 °C was confirmed to be a crucial turning point for physiochemical properties, at which the graphitic structural changes occurred, pore collapsed, and potassium salts released. Bamboo age was proved to enhance the stability. Pearson correlation coefficient (PCC) analysis revealed that the pyrolysis temperature was positively correlated (
p
< 0.01) with ash (0.76), FC (0.97), AI (0.81), R
50
(0.77), and C–C/C = C/C–H (0.87). Conversely, negative correlations (
p
< 0.01) were observed with VM (−0.91), O/C (0.88), H/C (−0.95), (N + O)/C (−0.87), C loss (−0.79), and labile organic-C (−0.78). Additionally, bamboo age was negatively correlated (
p
< 0.01) with C loss (−0.40), volatile organic-C (−0.63), labile organic-C (−0.45), and recalcitrant organic-C (−0.40), but positively associated with R
50
(0.54), refractory organic-C (0.42), and inorganic-C (0.52). Bamboo parts did not exhibit significant correlations with char properties.
Graphical Abstract
Highlights
500 °C and 800 °C served as key turning points for the properties of biochar.
Bamboo age had a positive effect on thermal stability and chemical stability.
There was no significant difference in properties between different parts (internodes and nodes) of bamboo.
We demonstrate a passively Q-switched Yb3+/Er3+ co-doped fiber (YEDF) laser using a filmy sodium carboxymethylcellulose (NaCMC)-based Cu1.8S nanocrystals (NCs) saturable absorber (SA). Cu1.8S NCs SA ...exhibit a broad absorption band from 600 nm to more than 2500 nm. By placing Cu1.8S NCs SA into a YEDF laser cavity, stable passively Q-switched laser with a central wavelength of similar to 1567.2 nm was achieved at a threshold pump power of similar to 1.4 W. On gradually increasing the pump power from 1.4 W to 5.6 W, the repetition rate of Q-switched laser increases from 16.6 kHz to 51.14 kHz and the pulse duration decreases from 8.7 mu s to 2 mu s. Particularly, we measure the output power of Q-switched lasers based on two types of plasmonic materials, Cu1.8S NCs and gold nanorods (GNRs). The maximum output power of the Q-switched laser based on Cu1.8S NCs SA is 3-4 times higher than that based on GNRs SA owing to weak photothermal effect of Cu1.8S NCs. These results show that Cu1.8S NCs are promising SAs for constructing high power pulse lasers.
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