DMF as an Additive in a Two-Step Spin-Coating Method for 20% Conversion Efficiency in Perovskite Solar Cells

DMF as an additive has been employed in FAI/MAI/IPA (FA= CH₂(NH₂)₂, MA = CH₃NH₃, IPA = isopropanol) solution for a two-step multicycle spin-coating method in order to prepare high-quality FA_<i>x</i>MA_1–<i>x</i>PbI_2.55Br_0.45 perovskite films. Further investigation reveals that the existence of DMF in the FAI/MAI/IPA solution can facilitate perovskite conversion, improve the film morphology, and reduce crystal defects, thus enhancing charge-transfer efficiency. By optimization of the DMF amount and spin-coating cycles, compact, pinhole-free perovskite films are obtained. The nucleation mechanisms of perovskite films in our multicycle spin-coating process are suggested; that is, the introduction of DMF in the spin-coating FAI/MAI/IPA solution can lead to the formation of an amorphous phase PbX₂–AI–DMSO–DMF (X = I, Br; A = FA, MA) instead of intermediate phase (MA)₂Pb₃I₈·2DMSO. This amorphous phase, similar to that in the one-step method, can help FAI/MAI penetrate into the PbI₂ framework to completely convert into the perovskite. As high as 20.1% power conversion efficiency (PCE) has been achieved with a steady-state PCE of 19.1%. Our work offers a simple repeatable method to prepare high-quality perovskite films for high-performance PSCs and also help further understand the perovskite-crystallization process

Application of Cesium on the Restriction of Precursor Crystallization for Highly Reproducible Perovskite Solar Cells Exceeding 20% Efficiency

In this study, we systematically explored the mixed-cation perovskite Cs<i>_x</i>(MA_0.4FA_0.6)_1–<i>x</i>PbI₃ fabricated via sequential introduction of cations. The details of the effects of Cs⁺ on the fabrication and performance of inorganic–organic mixed-cation perovskite solar cells examined in detail in this study are beyond the normal understanding of the adjusting band gap. It is found that a combined intercalation of Cs⁺ and dimethyl sulfoxide (DMSO) in PbI₂–DMSO precursor film formed a strong and steady coordinated intermediate phase to retard PbI₂ crystallization, suppress yellow nonperovskite δ-phase, and obtain a highly reproducible perovskite film with less defects and larger grains. The Cs-contained triple-cation-mixed perovskite Cs_0.1(MA_0.4FA_0.6)_0.9PbI₃ devices yield over 20% reproducible efficiencies, superior stabilities, and fill factors of around 0.8 with a very narrow distribution

Identification of Conserved and Novel microRNAs in Cashmere Goat Skin by Deep Sequencing

<div><p>MicroRNAs (miRNAs) are a class of small RNAs that play significant roles in regulating the expression of the post-transcriptional skin and hair follicle gene. In recent years, extensive studies on these microRNAs have been carried out in mammals such as mice, rats, pigs and cattle. By comparison, the number of microRNAs that have been identified in goats is relatively low; and in particular, the miRNAs associated with the processes of skin and hair follicle development remain largely unknown. In this study, areas of skin where the cashmere grows in anagen were sampled. A total of 10,943,292 reads were obtained using Solexa sequencing, a high-throughput sequencing technology. From 10,644,467 reads, we identified 3,381 distinct reads and after applying the classification statistics we obtained 316 miRNAs. Among them, using conservative identification, we found that 68 miRNAs (55 of these are confirmed to match known sheep and goat miRNAs in miRBase ) are conserved in goat and have been reported in NCBI; the remaining 248 miRNA were conserved in other species but have not been reported in goat. Furthermore, we identified 22 novel miRNAs. Both the known and novel miRNAs were confirmed by a second sequencing using the same method as was used in the first. This study confirmed the authenticity of 316 known miRNAs and the discovery of 22 novel miRNAs in goat. We found that the miRNAs that were co-expressed in goat and sheep were located in the same region of the respective chromosomes and may play an essential role in skin and follicle development. Identificaton of novel miRNAs resulted in significant enrichment of the repertoire of goat miRNAs.</p> </div

Additional file 1 of Transplantation of the LRP1high subpopulation of human umbilical cord-derived mesenchymal stem cells improves ovarian function in mice with premature ovarian failure and aged mice

Additional file 1. Supplementary Figures S1–S9

Integrated Trilayered Silk Fibroin Scaffold for Osteochondral Differentiation of Adipose-Derived Stem Cells

Repairing osteochondral defects (OCD) remains a formidable challenge due to the high complexity of native osteochondral tissue and the limited self-repair capability of cartilage. Osteochondral tissue engineering is a promising strategy for the treatment of OCD. In this study, we fabricated a novel integrated trilayered scaffold using silk fibroin and hydroxyapatite by combining paraffin-sphere leaching with a modified temperature gradient-guided thermal-induced phase separation (TIPS) technique. This biomimetic scaffold is characterized by three layers: a chondral layer with a longitudinally oriented microtubular structure, a bony layer with a 3D porous structure and an intermediate layer with a dense structure. Live/dead and CCK-8 tests indicated that this scaffold possesses good biocompatibility for supporting the growth, proliferation, and infiltration of adipose-derived stem cells (ADSCs). Histological and immunohistochemical stainings and real-time polymerase chain reaction (RT-PCR) confirmed that the ADSCs could be induced to differentiate toward chondrocytes or osteoblasts in vitro at chondral and bony layers in the presence of chondrogenic- or osteogenic-induced culture medium, respectively. Moreover, the intermediate layer could play an isolating role for preventing the cells within the chondral and bony layers from mixing with each other. In conclusion, the trilayered and integrated osteochondral scaffolds can effectively support cartilage and bone tissue generation in vitro and are potentially applicable for OC tissue engineering in vivo

Relationship of serum total cholesterol and triglyceride with risk of mortality in maintenance hemodialysis patients: a multicenter prospective cohort study

The relationship between serum total cholesterol (TC) and triglyceride (TG) levels and mortality in maintenance hemodialysis (MHD) patients remains inconsistent. We aimed to explore the individual and combined association of TC and TG levels with the risk of mortality in Chinese MHD patients. 1036 MHD patients were enrolled in this multicenter, prospective cohort study. The serum levels of total cholesterol and triglycerides were measured at baseline. The primary outcome was all-cause mortality and secondary outcome was cardiovascular disease (CVD) mortality. During a median follow-up duration of 4.4 years (IQR= 2.0–7.9 years), 549 (53.0%) patients died, and 297 (28.7%) deaths were attributed to CVD. Compared with patients with TC levels in the first three quartiles ( Conclusions: In MHD patients in southern China, higher TC levels were associated with higher risk of mortality, while higher TG levels were related to lower risk of mortality. Patients with lower TC and higher TG levels had the best survival prognosis.</p