Room-Temperature Phase Transition Material with Switchable Second-Order Nonlinear Optical Properties

Phase transition materials with switchable second-order nonlinear optical (NLO) properties have attracted extensive attention because of their great application potential in photoelectric switches, sensors, and modulators, while metal-free organics with NLO switchability near room temperature remain scarce. Herein, we report a hydrogen-bonded metal-free organic crystal, 2-methylpropan-2-aminium 2,2-dimethylpropanoate (1), exhibiting a room-temperature phase transition and favorable NLO switchability. Through investigations on its thermal anomalies, dielectric properties, and crystal structures, we uncover that 1 holds a near-room-temperature phase transition at 303 K from noncentrosymmetric point group C2v to centrosymmetric one D2h, which is attributed to the order-disorder transformations of both tert-butylamine cations and dimethylpropionic acid anions. Accompanied by symmetry change during the phase transition, 1 exhibits reversible and repeatable NLO "on-off" switchability with a desirable switching contrast ratio of ca. 19 between high and low NLO states. This discovery demonstrates a metal-free organic crystal with NLO switching behavior near room temperature, serving as a promising candidate in smart and ecofriendly photoelectric functional materials and devices.

Biodegradable ferroelectric molecular crystal with large piezoelectric response

Transient implantable piezoelectric materials are desirable for biosensing, drug delivery, tissue regeneration, and antimicrobial and tumor therapy. For use in the human body, they must show flexibility, biocompatibility, and biodegradability. These requirements are challenging for conventional inorganic piezoelectric oxides and piezoelectric polymers. We discovered high piezoelectricity in a molecular crystal HOCH2(CF2)3CH2OH [2,2,3,3,4,4-hexafluoropentane-1,5-diol (HFPD)] with a large piezoelectric coefficient d33 of ~138 picocoulombs per newton and piezoelectric voltage constant g33 of ~2450 × 10-3 volt-meters per newton under no poling conditions, which also exhibits good biocompatibility toward biological cells and desirable biodegradation and biosafety in physiological environments. HFPD can be composite with polyvinyl alcohol to form flexible piezoelectric films with a d33 of 34.3 picocoulombs per newton. Our material demonstrates the ability for molecular crystals to have attractive piezoelectric properties and should be of interest for applications in transient implantable electromechanical devices.

A Sn-Based Hybrid Ferroelastic Semiconductor with High-Temperature Dielectric Switching

Organic-inorganic halide hybrids have been extensively developed and used in optoelectronic devices because of their superior performance such as ease of assembly, flexible structural tunability, and excellent optoelectronic properties. Ferroelastic strain might be used to modulate and control photoelectric properties such as photovoltaic voltage, while organic-inorganic hybrid ferroelastic semiconductors remain relatively unexplored. Herein, we successfully design a new Sn-base, lead-free hybrid ferroelastic semiconductor, [TPMA]2[SnCl6] (TPMA = benzyl trimethylammonium). It undergoes a high-temperature -3mF-1-type ferroelastic phase transition at 408 K, and intriguingly, its ferroelastic domains can be simultaneously switched under the stimulation of external heat and stress. The ferroelastic phase transition might be derived from the order-disorder transition of organic cations during heating and cooling. Moreover, [TPMA]2[SnCl6] also demonstrates a high-temperature dielectric switching property around 408 K, which has good stability and reproducibility. With those benefits, [TPMA]2[SnCl6] shows great potential in applications such as energy storage devices, optoelectronic devices, shape memory, intelligent switches, and so on.

[Initial experience of transcatheter edge-to-edge repair guided by only transesophageal echocardiography in the treatment of tricuspid insufficiency]

Objective: To evaluate the feasibility and safety of transcatheter tricuspid valve edge-to-edge repair guided by only transesophageal echocardiography (TEE). Methods: Patients with severe tricuspid regurgitation in Fuwai Yunnan Cardiovascular Hospital who met the inclusion criteria based on clinical and echocardiographic evaluationand underwent transcatheter tricuspid valve edge-to-edge repair between January 2022 and May 2023 were prospectively enrolled. The procedure was performed under general anesthesia with endotracheal intubation and solely guided by TEE. The patients underwent clinical evaluation, electrocardiogram and transthoracic echocardiography one month after the procedure. Results: A total of 22 patients (12 males and 10 females) were included, with an average age of (71.3±6.7) years. All 22 patients successfully underwent the transcatheter tricuspid valve edge-to-edge repair under TEE guidance, with an average of (1.5±0.6) clips implanted. Immediately after procedure, six patients had no or trace regurgitation, 15 patients had mild regurgitation, and one patient had moderate regurgitation. All 22 patients completed 30-day follow-up, with four patients having trace regurgitation, 17 patients having mild regurgitation, and one patient having moderate regurgitation. Echocardiographic measurements revealed that effective regurgitant orifice area, regurgitant volume, vena contracta width, and proximal isovelocity surface area radius significantly decreased after the procedure (all P<0.05). In addition, inferior vena cava width, right atrial volume, tricuspid annular diameter, and right ventricular end-diastolic diameter significantly improved (all P<0.05), but tricuspid annular plane systolic excursion and right ventricular fractional area change did not show significant differences compared with those before the procedure (both P>0.05). Conclusion: It has been preliminarily confirmed that transcatheter tricuspid valve edge-to-edge repair solely guided by TEE is feasible and safe, but requires more large-scale studies for further validation.

A ZnIn2S4@ReS2/AgInS2-based photoelectrochemical aptasensor for the ultrasensitive detection of kanamycin

An ultrasensitive photoelectrochemical (PEC) aptasensor was originally designed by using ZnIn2S4/ReS2 as a photoactive material and AgInS2 as a signal amplifier. The signal amplifier AgInS2 was incubated on the terminal of H-DNA (immobilized on the ZnIn2S4/ReS2/FTO surface), leading to an enhanced photocurrent response. Then, due to the introduction of DNA2, the formation of a double-stranded structure caused AgInS2 to keep away from the electrode surface, and the photocurrent was reduced. In the presence of kanamycin, DNA2 was released from the system due to the competition relationship, and a restored photocurrent response was obtained. The combination of ZnIn2S4/ReS2 and AgInS2 accelerated the electron transfer and enhanced the separation efficiency of photogenerated electron-hole pairs, resulting in an improved performance of the PEC aptasensor, which was capable of accurate and sensitive detection of kanamycin in actual samples.

[Risks to predict blood loss and cranial nerve injury in carotid body paraganglioma resection]

Objective: To investigate clinical and imaging parameters to predict blood loss and cranial nerve injury (CNI) following carotid body paraganglioma (CBP) resection. Methods: A retrospective examination of clinical and imaging data was conducted on 63 patients who underwent CBP resection at Xiangya Hospital of Central South University from January 2016 to December 2022, including 23 males and 40 females, aged 26-87 years old. Three imaging parameters including tumor volume, the angle of contact with the internal carotid artery (ICA), and the distance to the base of skull (DTBOS) were gauged using the IMEDPACS software on CTA and MR imaging. The predictive efficacies of age, gender, Shamblin classification, and three imaging parameters for blood loss and CNI following surgery were analysed. Logistic composite parameter models were constructed and their predictive validity was assessed. Results: Multivariate logistic regression analysis underscored that only tumor volume (OR=1.381,95%CI:1.167-1.507,P=0.001) showed significant statistical correlations with blood loss following surgery. Area under curve (AUC) values of 0.910 for receiver operating characteristic (ROC) curves showed a sensitivity of 1.000 and a specificity of 0.694. Tumor volume (OR=1.126,95%CI:1.030-1.231, P=0.002) and DTBOS (OR=0.225,95%CI:0.081-0.630,P=0.005) were significantly associated with postoperative CNI. The analysis of logistic composite model showed AUC values for tumor volume, DTBOS and combination of the two parameters were 0.858, 0.788, and 0.872, respectively. The model for combination of tumor volume and DTBOS also proved superior in predicting postoperative CNI (Z=3.106, P<0.001), with a sensitivity of 0.833 and a specificity of 0.769. Conclusions: Tumor volume and DTBOS emerged as effective predictors for blood loss and/or CNI in patients with CBP resection. Moreover, the logistic composite parameter model outclassed single-parameter models in terms of their predictive clinical value.

H/F Substitution Achieved Enantiomeric Organic Inorganic Hybrid Perovskites and Trigonal Structure [DMFP]3(CdBr3)(CdBr4)

Organic-inorganic hybrid perovskites (OIHPs) have been emerging as a hot research topic due to their potential applications in energy storage, semiconductors, and electronic devices. Herein, we systematically investigated the synthesis and phase transition behaviors of the enantiomeric OIHPs, (R) and (S)-N,N-dimethyl-3-fluoropyrrolidinium cadmium bromide ([DMFP][CdBr3]), and the hybrid trigonal structure [DMFP]3 (CdBr3)(CdBr4). The enantiomers have a mirror-symmetric structure and enhanced solid-state phase transition points of 417 and 443 K, in contrast to the nonfluorinated parent compound, N,N-dimethyl-pyrrolidinium cadmium bromide ([DMP][CdBr3], 385 K). Moreover, racemic H/F substitution on the pyrrolidinium cations leads to the formation of a trigonal compound, showing above-room-temperature structural phase transition and dominant ferroelasticity. This work discovers chiral enantiomeric OIHPs through H/F substitution, demonstrating a useful chemical synthesis strategy for exploring novel phase transition materials.

Dual Breaking of Molecular Orbitals and Spatial Symmetry in an Optically Controlled Ferroelectric

As particles carry quantified energy, photon radiation enables orbital transitions of energy levels, leading to changes in the spin state of electrons. The resulting switchable structural bistability may bring a new paradigm for manipulating ferroelectric polarization. However, the studies on molecular orbital breaking in the ferroelectric field remain blank. Here, for the first time, a new mechanism of ferroelectrics-dual breaking of molecular orbitals and spatial symmetry, demonstrated in a photochromic organic crystal with light-induced polarization switching, is formally proposed. By alternating the ultraviolet/visible light irradiation, the states of electron spin and the radial distribution p atomic orbitals experience a change, showing a reversible switch from "shoulder-to-shoulder" form to a "head-to-head" form. This reflects a reversible conversion between π and σ bonds, which induces and couples with the variation of spatial symmetry. The intersection of spatial symmetry breaking and molecular orbital breaking in ferroelectrics present in this work will be more conducive to data encryption and anticounterfeiting.

[Comparison on the efficacy of Chinese-made novel-designed mechanical-locked and elastic self-locked transcatheter edge-to-edge repair system in the treatment of patients with functional mitral regurgitation]

Objective: To evaluate and compare the short-term efficacy of domestic mechanical-locked (Clip2Edge) and elastic self-locked (ValveClip) transcranial mitral valve edge-to-edge interventional repair (TEER) devices in the treatment of functional mitral regurgitant valves. Methods: In this retrospective non-randomized comparative study, patients underwent TEER procedure in Fuwai Yunnan Cardiovascular Disease Hospital from May 2022 to April 2023 for heart failure combined with moderate to severe or severe functional mitral valve were divided into Clip2Edge and ValveClip groups based on the TEER system used. Baseline, perioperative, and postoperative 30 d follow-up data were collected and compared between the two groups. The primary outcome was the success rate on the 30 d post operation, while secondary outcomes included immediate postoperative technical success rate and the incidence of all-cause mortality on the 30 d post operation, readmission rate of acute heart failure, cerebral infarction, severe bleeding, and other serious adverse events rates. Results: A total of 60 patients were enrolled, 34 patients were in the Clip2Edge group and 26 in the ValveClip group, mean age was (63.8±9.3) years, and 24 patients (40%) were female. There were no significant differences in baseline data of age, cardiac function, comorbidities, mitral regurgitation 4+(19(73%) vs. 29(85%)), the end-diastolic volume of left ventricle ((220.8±91.2) ml vs. (210.8±71.7) ml) between the two groups (all P>0.05). The technical success rate immediately after the procedure was 100%. There were no readmission of acute heart failure, death, cerebral infarction, severe bleeding, and other serious adverse events up to the 30 d follow-up. Device success rate was similar between the ValveClip group (24 cases (100%)) and the Clip2Edge group (27 cases (96%)) (P>0.05). Conclusion: Both types of novel domestic TEER devices are safe and feasible in treating patients with functional mitral regurgitation.

[Analysis of mortality trend and characteristic of chronic obstructive pulmonary disease among residents in China from 2004 to 2020]

Objective: To analyze the mortality trend and characteristics of chronic obstructive pulmonary disease (COPD) among residents in China from 2004 to 2020. Methods: From the area, gender, region, and age dimensions, the Joinpoint regression model was used to analyze the trend of COPD mortality rate from 2004 to 2020, extracted from the China Death Surveillance Dataset. Results: From 2004 to 2020, the mortality rate and age-adjusted mortality rate of COPD showed a downward trend (AAPC=-3.68%, P<0.001; AAPC=-7.27%, P<0.001), which were consistent with urban and rural subpopulations (mortality rate: AAPC=-3.62%, P=0.009, AAPC=-3.23%, P=0.014; age-adjusted mortality rate: AAPC=-7.26%, P<0.001, AAPC=-6.78%, P<0.001). The mortality rate of COPD in rural was higher than that of urban subpopulations (P<0.001). Also, the mortality rate and age-adjusted mortality rate of COPD showed a downward trend in males and females (mortality rate: AAPC=-3.00%, P<0.001, AAPC=-4.37%, P<0.001; age-adjusted mortality rate: AAPC=-6.73%, P<0.001, AAPC=-8.11%, P<0.001), and the COPD mortality rate for male was generally higher than female (P<0.001). Meanwhile, the mortality rate of COPD in eastern, central and western regions also showed a downward trend (AAPC=-3.87%, P<0.001; AAPC=-3.12%, P<0.001; AAPC=-1.37%, P=0.001), and western regions were significantly higher than that in central (P<0.001) and eastern (P<0.001) regions. The mortality rate of COPD in the age group of Chinese people showed a downward trend in<45, 45-59, and≥60 years groups (AAPC=-9.48%, P<0.001; AAPC=-9.03%, P<0.001; AAPC=-5.91%, P<0.001). Among them,≥60 years groups was significantly higher than that in<45 (P<0.001) and 45-59 (P<0.001) years groups, and the decline rate was slowest. Conclusion: In China, the mortality rate of COPD decreases from 2004 to 2020, and more efforts are needed to reduce COPD mortality, especially in western regions, rural populations, males and the elderly.

[Multi-component content determination of Dracocephalum tanguticum by quantitative analysis of multi-components by single-marker]

This study aims to establish a method for the simultaneous determination of 7 active components in Dracocephalum tanguticum and to evaluate the quality of medicinal materials from different habitats. The method was established with high performance liquid chromatography(HPLC) and the gradient elution was performed with the mobile phase of acetonitrile-methanol-0.2% phosphoric acid solution at a column temperature of 35 ℃, an injection volume of 15 μL, and a flow rate of 0.6 mL·min~(-1). The detection wavelength was set as 215 nm. With rosmarinic acid as the internal reference, the relative correction factors and the content of other 6 components were calculated. The results were compared with those obtained with the external standard method. The results showed that the samples from Huangzhong county, Qinghai province had the best quality, with the highest content of p-hydroxybenzoic acid, cosmosiin, rosmarinic acid, oleanolic acid, and ursolic acid(9.29, 12.14, 6.02, 3.11, 17.67 mg·g~(-1) respectively). The samples from Chaya county, Tibet autonomous region ranked the second, with the highest content of betulin and betulinic acid(15.53, 7.17 mg·g~(-1), respectively). The method is accurate, reliable, and repeatable and suitable for the simultaneous determination of multiple components in D. tanguticum. The content of functional components varied in the samples from different producing areas and can be used as the indicator for the quality evaluation of medicinal materials.

Ferroelectric Phase Transition Driven by Switchable Covalent Bonds

The mechanism on ferroelectric phase transitions is mainly attributed to the displacive and/or order-disorder transition of internal components since the discovery of the ferroelectricity in 1920, rather than the breaking and recombination of chemical bonds. Here, we demonstrate how to utilize the chemical bond rearrangement in a diarylethene-based crystal to realize the light-driven mm2F1-type ferroelectric phase transition. Such a photoinduced phase transition is entirely driven by switchable covalent bonds with breaking and reformation, enabling the reversible light-controllable ferroelectric polarization switching, dielectric and nonlinear optical bistability. Moreover, light as quantized energy can achieve contactless, nondestructive, and remote-control operations. This work proposes a new mechanism of ferroelectric phase transition, and highlights the significance of photochromic molecules in designing new ferroelectrics for photocontrol data storage and sensing.

[Geochemical Characteristics of Cd in Different Parent Soils in Karst Area and Prediction of Cd Content in Maize]

The naturally high background value region of Cd derived from the weathering of carbonate has received wide attention. Due to the significant difference in soil physicochemical properties, soil Cd content, and bioavailability of different parent materials in the karst area, there are certain limitations in using the total soil Cd content to classify the environmental quality of cultivated land. In this study, surface soil and maize samples of eluvium and alluvial parent material in typical karst areas were collected systematically; the contents of maize Cd, soil Cd, pH, and oxides were analyzed, the Cd geochemical characteristics of different parent soils and the influencing factors of their bioavailability were revealed, and scientific and effective arable land use zoning suggestions based on the prediction model were suggested. The results showed that the physicochemical properties of different parent material soils in the karst area were obviously different. The alluvial parent material soil had low Cd content but high bioavailability, and the maize Cd exceeding rate was high. The maize Cd bioaccumulation factor was significantly negatively correlated with soil CaO, pH, Mn, and TC, and the correlation coefficients were -0.385, -0.620, -0.484, and -0.384, respectively. Compared with the multiple linear regression prediction model, using the random forest model to predict the maize Cd enrichment coefficient had higher accuracy and precision. Furthermore, a new scheme for the safe utilization of cultivated land at the plot scale based on soil Cd and predicted crop Cd content was proposed in this study, making full use of arable land resources to ensure crop safety.

High-T c Single-Component Organosilicon Ferroelectric Crystal Obtained by H/F Substitution

Organic single-component ferroelectrics are highly desirable for their low molecular mass, light weight, low processing temperature, and excellent film-forming properties. Organosilicon materials with a strong film-forming ability, weather resistance, nontoxicity, odorlessness, and physiological inertia are very suitable for device applications related to the human body. However, the discovery of high-T _c organic single-component ferroelectrics has been very scarce, and the organosilicon ones even less so. Here, we used a chemical design strategy of H/F substitution to successfully synthesize a single-component organosilicon ferroelectric tetrakis(4-fluorophenylethynyl)silane (TFPES). Systematic characterizations and theory calculations revealed that, compared with the parent nonferroelectric tetrakis(phenylethynyl)silane, fluorination caused slight modifications of the lattice environment and intermolecular interactions, inducing a 4/mmmFmm2-type ferroelectric phase transition at a high T _c of 475 K in TFPES. To our knowledge, this T _c should be the highest among the reported organic single-component ferroelectrics, providing a wide operating temperature range for ferroelectrics. Moreover, fluorination also brought about a significant improvement in the piezoelectric performance. Combined with excellent film properties, the discovery of TFPES provides an efficient path for designing ferroelectrics suitable for biomedical and flexible electronic devices.

Remarkable Enhancement of Piezoelectric Performance by Heavy Halogen Substitution in Hybrid Perovskite Ferroelectrics

Piezoelectric materials that enable electromechanical conversion have great application value in actuators, transducers, sensors, and energy harvesters. Large piezoelectric (d₃₃) and piezoelectric voltage (g₃₃) coefficients are highly desired and critical to their practical applications. However, obtaining a material with simultaneously large d₃₃ and g₃₃ has long been a huge challenge. Here, we reported a hybrid perovskite ferroelectric [Me₃NCH₂Cl]CdBrCl₂ to mitigate and roughly address this issue by heavy halogen substitution. The introduction of a large-size halide element softens the metal-halide bonds and reduces the polarization switching barrier, resulting in excellent piezoelectric response with a large d₃₃ (∼440 pC/N), which realizes a significant optimization compared with that of previously reported [Me₃NCH₂Cl]CdCl₃ (You et al. Science2017, 357, 306-309). More strikingly, [Me₃NCH₂Cl]CdBrCl₂ simultaneously shows a giant g₃₃ of 6215 × 10^-3 V m/N, far exceeding those of polymers and conventional piezoelectric ceramics. Combined with simple solution preparation, easy processing of thin films, and a high Curie temperature of 373 K, these attributes make [Me₃NCH₂Cl]CdBrCl₂ promising for high-performance piezoelectric sensors in flexible, wearable, and biomechanical devices.

Axial-Chiral BINOL Multiferroic Crystals with Coexistence of Ferroelectricity and Ferroelasticity

Chirality exists everywhere from natural amino acids to particle physics. The introduction of point chirality has recently been shown to be an efficient strategy for the construction of molecular ferroelectrics. In contrast to point chirality, however, axial chirality is rarely used to design ferroelectrics so far. Here, based on optically active 1,1'-bi-2-naphthol (BINOL), which has been applied extensively as a versatile chiral reagent in asymmetric catalysis, chiral recognition, and optics, we successfully design a pair of axial-chiral BINOL multiferroics, (R)-BINOL-DIPASi and (S)-BINOL-DIPASi. They experience a 2F1-type full ferroelectric/ferroelastic phase transition at a high temperature of 362 and 363 K, respectively. Piezoelectric force microscopy and polarization-voltage hysteresis loops demonstrate their ferroelectric domains and domain switching, and polarized light microscopy visualizes the evolution of stripe-shaped ferroelastic domains. The axial-chiral BINOL building block promotes the generation of the polar structure and ferroelectricity, and the organosilicon component increases the rotational energy barrier and thus the phase transition temperature. This work presents the first axial-chiral high-temperature multiferroic crystals, offering an efficient path for designing molecular multiferroics through the introduction of axial chirality.

Contactless Manipulation of Write-Read-Erase Data Storage in Diarylethene Ferroelectric Crystals

The optical manipulation of polarization has gained widespread attention because it offers a promising route to new contactless memories and switches. However, the current research basically focuses on the photocontrol of data storage rather than data reading, which cannot realize the whole process of contactless write-read-erase data storage. Here, we present a pair of enantiomorphic diarylethene derivative ferroelectric crystals, showing a light-driven phase transition triggered by photoisomerization between the open and closed forms. Under the visible light, they exhibit a binary-domain state in the open form with white color and the band gap of 3.26 eV, while they show a single-domain state in the closed form with blue color and the band gap of 1.68 eV after UV irradiation of 254/365 nm. In addition to writing and erasing ferroelectric domains with light, we can also use light to read their color to determine the polarization state of domains. Moreover, diarylethene derivatives have better thermal stability, higher photoexcited conversion efficiency, and larger changes of the absorption wavelength between two isomers than those in salicylideneaniline derivatives. This work not only discovers the first diarylethene-based ferroelectric crystals but also successfully realizes completely contactless manipulation of write-read-erase data storage in the organic ferroelectric semiconductors.

The Effect of Visual Mnemonics and the Presentation of Character Pairs on Learning Visually Similar Characters for Chinese-As-Second-Language Learners

This study investigates the effects of visual mnemonics and the methods of presenting learning materials on learning visually similar characters for Chinese-as-second-language (CSL) learners. In supporting CSL learners to build robust orthographic representations in Chinese, addressing the challenges of visual similarity of characters (e.g., and ) is an important issue. Based on prior research on perceptual learning, we tested three strategies that differ in the extent to which they promote interrelated attention to the form and meaning of characters: (1) Stroke Sequence, a form-emphasis strategy, (2) Key-images, a form + meaning strategy utilizing visual code, (3) Pithy Formulas with Key-images, a form + meaning strategy combining visual and verbal codes. A pretest-posttest equivalent-group design was adopted. The independent variables were the learning strategy, the method of presenting character pairs (visually similar vs. dissimilar), and testing time. The dependent variables were learners' proportions of accurate responses to reading and writing Chinese characters through a posttest (immediately performed after learning) and a delayed posttest (1 week after learning); a learner experience survey was also administered to investigate learners' opinions on each strategy. Sixty-six non-beginning learners of Chinese participated; they were randomly assigned to one of the two groups in which participants learned ten characters via the three strategies, respectively, differing between whether the characters were presented in similar pairs or dissimilar pairs. Data were analyzed via three-way ANCOVAs. The Pithy Formulas with Key-images and the Key-images generally yielded higher writing accuracy than Stroke Sequence immediately after learning. Notably, the advantage of the Pithy Formulas with Key-images (verbal and visual) over the Key-images (visual) on writing was specific to the participants that learned with visually similar pairs rather than those that learned with dissimilar pairs. All strategies were effective for reading, yet learners' experience ratings favored the two form + meaning strategies over the strategy that focused primarily on form. Suggestions for future research and pedagogical implications on learning visually similar characters were offered.

Domain memory effect in the organic ferroics

Shape memory alloys have been used extensively in actuators, couplings, medical guide wires, and smart devices, because of their unique shape memory effect and superelasticity triggered by the reversible martensitic phase transformations. For ferroic materials, however, almost no memory effects have been found for their ferroic domains after reversible phase transformations. Here, we present a pair of single-component organic enantiomorphic ferroelectric/ferroelastic crystals, (R)- and (S)-N-3,5-di-tert-butylsalicylidene-1-(1-naphthyl)ethylamine SA-NPh-(R) and SA-NPh-(S). It is notable that not only can their ferroic domain patterns disappear and reappear during reversible thermodynamic phase transformations, but they can also disappear and reappear during reversible light-driven phase transformations induced by enol-keto photoisomerization, both of which are from P1 to P21 polar space groups. Most importantly, the domain patterns are exactly the same in the initial and final states, demonstrating the existence of a memory effect for the ferroic domains in SA-NPh-(R) and SA-NPh-(S). As far as we are aware, the domain memory effect triggered by both thermodynamic and light-driven ferroelectric/ferroelastic phase transformations remains unexplored in ferroic materials. Thermal and optical control of domain memory effect would open up a fresh research field for smart ferroic materials.

[(Histamine)(18-crown-6)2][BF4]2 is a high-temperature piezoelectric

We discovered that [(histamine)(18-crown-6)₂][BF₄]₂ is a high-temperature host-guest inclusion complex that presents decent piezoelectric properties (d₃₃ = 5 pC/N), undergoes a phase transition at 406 K, and also possesses potential ferroelectricity. This work provides a new idea for constructing host-guest inclusion piezoelectrics.

miR-664b-3p inhibits colon cell carcinoma via negatively regulating Budding uninhibited by benzimidazole 3

MiR-664b-3p has been reported to play a crucial role in cancer progression. This research explores the biological effect and molecular mechanisms of miR-664b-3p in cell proliferation, apoptosis, migration, and invasion of colon cancer. The expression level of miR-664b-3p and Budding uninhibited by benzimidazole 3 (Bub3) in colon cancer cell lines and tissues were detected and analyzed using quantitative real-time PCR and bioinformatics method. The Western blot measured the expression level of proliferation-related, migration-related, and apoptosis-related proteins. CCK-8 assessed cell viability, and the cell proliferation, migration, and invasion were detected by the Edu assay, wound-healing assay, and transwell assay, respectively. Annexin/propidium iodide (PI) assays detected apoptosis of cells. The target of miR-664b-3p was predicted by bioinformatics methods and then validated by gene engineering technology. MiR-664b-3p was downregulated in colon cancer tissues and cells. The cell proliferation, migration, and invasion of cells were inhibited after transfecting by miR-664b-3p mimics, whereas apoptosis was promoted. Over-expression of miR-664b-3p could reduce the expression of proliferation-promoted proliferating cell nuclear antigen (PCNA), proliferation marker protein Ki-67 (Ki-67), migration-promoted Cyclooxygenase-2 (COX-2), Matrix Metallopeptidase 2 (MMP-2), and Matrix Metallopeptidase 9 (MMP-9), and apoptosis-inhibited protein (Bcl-2) while increasing the expression of apoptosis-promoted BCL2-Associated X Protein (Bax), caspase-3, and caspase-9 proteins. The study indicated that miR-664b-3p plays a significant role in colon cancer and could regulate the progression of colon cancer tumor growth by suppressing the expression of BUB3 protein. These findings provide a novel strategy to screen and treat colon cancer.

Dual-channel control of ferroelastic domains in a host–guest inclusion compound

By replacing [PF6]− with the larger [TFSA]−, the phase transition temperature is increased from 305 K to 342 K in a host–guest inclusion ferroelastic crystal, [(3,4-DFA)(18-crown-6)][TFSA], which can realize dual-channel (thermal and stress) control of ferroelastic domains.

Recurrent Implantation Failure May Be Identified by a Combination of Diagnostic Biomarkers: An Analysis of Peripheral Blood Lymphocyte Subsets

BACKGROUND

Recurrent implantation failure (RIF) is a challenge during assisted reproductive technology (ART). In the present study, potential diagnostic biomarkers for the immune status of peripheral blood lymphocyte subsets in patients with RIF were analyzed, with the aim of identifying novel biomarkers that may predict RIF.

METHODS

A total of 41 participants, including 21 women with RIF and 20 fertile controls, were included in the present study. Functional analysis was performed and the cytokine status of natural killer (NK), T, CD8+ T, T helper (Th), and γδ T cells which are lymphocyte subsets in peripheral blood was measured using flow cytometry. Binary logistic regression analysis adjusted for T follicular helper 1 (Tfh1), Tfh2, Tfh17, and early NK cells was performed to determine the relationship between the peripheral blood lymphocyte subsets and RIF. Potential diagnostic biomarkers were assessed by logistic regression analysis and receiver operating characteristic curves.

RESULTS

There were significantly more Tfh1, Tfh17, and NK cells in the RIF group compared with the control group (all P < 0.05). However, the percentage of T, regulatory T (Tregs), and Tfh2 cells, as well as early inhibitory NK cells, was significantly lower in the RIF group compared with the control group (all P < 0.05). Following logistics regression analysis, Treg, Tfh17, and early inhibitory NK cells exhibited significant differences between the two groups. Combination diagnosis using these 3 biomarkers had a higher area under the curve of 0.900 (95% confidence interval: 0.808-0.992, P < 0.001) in the RIF group compared with that in the control group.

CONCLUSION

T, Tregs, Tfh1, Tfh2, Tfh17, NK cells, and early inhibitory NK cells may play important regulatory roles in embryo implantation. The combination of 3 molecular markers (Treg, Tfh17, and early inhibitory NK cells) could provide a high diagnostic value for women with RIF, thus providing novel potential biomarkers for RIF in ART. The present findings could provide a reference either for the clinical treatment of patients with RIF or for future large, well-designed studies.

Multichannel Control of Multiferroicity in Single-Component Homochiral Organic Crystals

A ferroelectric/ferroelastic is a material whose spontaneous polarization/strain can be switched by applying an external electric field/mechanical stress. However, the optical control of spontaneous polarization/strain remains relatively unexplored in crystalline materials, although photoirradiation stands out as a nondestructive, noncontact, and remote-controlled stimulus beyond stress or electric field. Here, we present two new organic single-component homochiral photochromic multiferroics, (R)- and (S)-N-3,5-di-tert-butylsalicylidene-1-4-bromophenylethylamine (SA-Ph-Br(R) and SA-Ph-Br(S)), which show a full ferroelectric/ferroelastic phase transition of 222F2 type at 336 K. Under photoirradiation, their spontaneous polarization/strain can be switched quickly within seconds and reversibly between two ferroelectric/ferroelastic phases with the respective enol and trans-keto forms triggered by structural photoisomerizations. In addition, they possess a superior acoustic impedance characteristic with a value of ∼2.42 × 10⁶ kg·s^-1·m^-2, lower than that of polyvinylidene fluoride (PVDF, (3.69-4.25) × 10⁶ kg·s^-1·m^-2), which can better match human tissues. This work realizes for the first time that multiple ferroic orders in single-component organic crystals with ultralow acoustic impedance can be simultaneously controlled and coupled by three physical channels (electric, stress, light fields), suggesting their great potential in multichannel data storage, optoelectronics, and related applications compatible with all-organic electronics and human tissues.

[Clinical effects of transplantation of turbocharged bipedicle deep inferior epigastric perforator flap in breast reconstruction]

Objective: To explore the clinical effects of transplantation of turbocharged bipedicle deep inferior epigastric perforator (DIEP) flap in breast reconstruction. Methods: A retrospective observational study was used. From December 2008 to December 2016, 24 patients who met the inclusion criteria were treated in the Department of Plastic Surgery of Hunan Cancer Hospital, all patients were female, aged 28-51 (36.5±1.6) years. All cases received turbocharged bipedicle DIEP flap for two-staged breast reconstruction. According to the patterns of turbocharged vessels anastomosis, the turbocharged bipedicle DIEP flaps with length of (27.5±0.3) cm and width of (12.8±1.4) cm, were divided into three types: distal end of pedicle anastomosis type, main branch of pedicle anastomosis type, and muscular branch of pedicle anastomosis type. After complete hemostasis in the donor region, the anterior sheath was repaired with intermittent suture, and umbilical reconstruction was completed. Two negative pressure drainage tubes were indwelled, and subcutaneous tissue and skin were sutured layer by layer. The specific ways of vascular anastomosis of the flap pedicle with the internal thoracic vessels of recipient site included anastomosing the proximal end of one artery and one vein, anastomosing the proximal and distal end of one artery and one vein, and anastomosing the proximal end of one artery and two veins. Postoperatively, the survival and blood supply of flaps were observed. The patients were followed up to observe the reconstructed breast shape satisfaction, donor site complications, abdominal wall function, and scar hyperplasia. Results: All turbocharged bipedicle DIEP flaps for two-staged breast reconstruction survived well, with good blood supply. During follow-up for 14 to 56 (20±6) months, the shape of reconstructed breasts was satisfied. Only linear scar was left in the donor sites of abdomen with no complications, and the function of abdominal wall was not affected. Conclusions: For patients with clear indications, transplantation of free turbocharged bipedicle DIEP flap is a safe, reliable, and satisfactory choice for breast reconstruction with autologous tissue.

Optical Control of Polarization Switching in a Single-Component Organic Ferroelectric Crystal

The optical control of polarization switching is attracting tremendous interest because photoirradiation stands out as a nondestructive, noncontact, and remote-control means beyond an electric or strain field. The current research mainly uses various photoexcited electronic effects to achieve the photocontrol polarization, such as a light-driven flexoelectric effect and a photovoltaic effect. However, since photochromism was discovered in 1867, the structural phase transition caused by photoisomerization has never been associated with ferroelectricity. Here, we successfully synthesized an organic photochromic ferroelectric with polar space group Pna2₁, 3,4,5-trifluoro-N-(3,5-di-tert-butylsalicylidene)aniline, whose color can change between yellow and orange via laser illumination. Its dielectric permittivity and spontaneous polarization can be switched reversibly with a photoinduced phase transition triggered by structural photoisomerization between the enol form and the trans-keto form. To our knowledge, this is the first photoswitchable ferroelectric crystal to achieve polarization switching through a structural phase transition triggered by photoisomerization. This finding paves the way toward photocontrol of smart materials and biomechanical applications in the future.

Coexistence of magnetic and electric orderings in a divalent Cr2+-based multiaxial molecular ferroelectric

Multiferroic materials have attracted great interest because of their underlying new science and promising applications in data storage and mutual control devices. However, they are still very rare and highly imperative to be developed. Here, we report an organic-inorganic hybrid perovskite trimethylchloromethylammonium chromium chloride (TMCM-CrCl3), showing the coexistence of magnetic and electric orderings. It displays a paraelectric-ferroelectric phase transition at 397 K with an Aizu notation of 6/mFm, and spin-canted antiferromagnetic ordering with a Néel temperature of 4.8 K. The ferroelectricity originates from the orientational ordering of TMCM cations, and the magnetism is from the [CrCl3]- framework. Remarkably, TMCM-CrCl3 is the first experimentally confirmed divalent Cr2+-based multiferroic material as far as we know. A new category of hybrid multiferroic materials is pointed out in this work, and more Cr2+-based multiferroic materials will be expectedly developed in the future.

Coupling sprinkler freshwater irrigation with vegetable species selection as a sustainable approach for agricultural production in farmlands with a history of 50-year wastewater irrigation

Soil contamination and crop risks of heavy metal(loid)s are widely reported after the long-term irrigation of treated wastewater, causing an adverse influence on agricultural sustainability. Here, we collected soils after 50 years of wastewater irrigation to cultivate cabbage (Brassica pekinensis L.), rape (Brassica chinensis L.), carrots (Daucus carota L.), and potatoes (Solanum tuberosum L.), using surface and sprinkler irrigation with freshwater and wastewater. In general, we found the statistically insignificant influence of short-term freshwater irrigation on the soil and vegetable metal(loid) concentrations. Most of the vegetables had potential adverse health risks with the relatively lower risks in carrots and potatoes, and most of the risks were contributed by As and Cd. Nevertheless, we observed negligible health risks for all studied metal(loid)s in potatoes under the freshwater irrigations. Besides, compared to wastewater irrigations, freshwater irrigations produced lower Cd health risks in all four vegetable species. Sprinkler irrigation with freshwater was a favorable approach for reducing the uptake of metal(loid)s from soils and the metal(loid) concentrations in aboveground parts. Our study highlights the possibility of reducing vegetable metal(loid) risks in contaminated farmlands via a combined approach of coupling the short-term decrease in their levels in irrigation water with vegetable species selection.

PFM (piezoresponse force microscopy)-aided design for molecular ferroelectrics

With prosperity, decay, and another spring, molecular ferroelectrics have passed a hundred years since Valasek first discovered ferroelectricity in the molecular compound Rochelle salt. Recently, the proposal of ferroelectrochemistry has injected new vigor into this century-old research field. It should be highlighted that piezoresponse force microscopy (PFM) technique, as a non-destructive imaging and manipulation method for ferroelectric domains at the nanoscale, can significantly speed up the design rate of molecular ferroelectrics as well as enhance the ferroelectric and piezoelectric performances relying on domain engineering. Herein, we provide a brief review of the contribution of the PFM technique toward assisting the design and performance optimization of molecular ferroelectrics. Relying on the relationship between ferroelectric domains and crystallography, together with other physical characteristics such as domain switching and piezoelectricity, we believe that the PFM technique can be effectively applied to assist the design of high-performance molecular ferroelectrics equipped with multifunctionality, and thereby facilitate their practical utilization in optics, electronics, magnetics, thermotics, and mechanics among others.

Effects of landfill refuse on the reductive dechlorination of pentachlorophenol and speciation transformation of heavy metals

Landfill refuse is a mixture of inorganic minerals and organic matter that is capable of undergoing complexation and redox reactions due to its active functional groups. Organic matter often combines with minerals in landfill refuse and it remains unclear whether this combination involves electron transfer. Therefore, the effects of landfill refuse composition on reductive dechlorination and speciation transformation of heavy metals were investigated in this study. Results show that landfill refuse comprises protein- and humic-like substances, aliphatic structures, and a large number of hydroxyl, carboxyl, quinoid and other active functional group. The electron donating capacity (0.09-0.26 μmol/g(C)) of landfill refuse was found to be higher than its electron accepting capacity (0.03-0.23 μmol/g(C)), indicating that electron donating groups (hydroxyl) were the main redox-active moieties, facilitating the reductive dechlorination of pentachlorophenol (PCP) by microorganism. Fe₂O₃, FeO and SiO₂ were the main inorganic minerals affecting PCP dechlorination. The speciation distribution of heavy metals in landfill refuse was determined by the BCR sequential extraction method. Results showed that Zn and Ni have high potential migration capacity, poor stability and the highest bioavailability, while Cr, Cu and Pb are relatively stable and have weak migration potential. The oxygen- and nitrogen-containing functional groups, aliphatic structures and aromatic carbon in landfill refuse can promote the transformation of Ni and Cr from an unstable to stable state. Protein-like substances exhibit a strong Cu binding ability, allowing Cu to combine with organic matter more easily than other assessed heavy metals. Both Fe₂O₃ and FeO affected the stability of Cu. FeO promoted the stabilization of Zn, whereas Fe₂O₃ and SiO₂ promoted Cu instability. These results could provide some references for the treatment of organic chlorides and the stabilization of heavy metals in landfill refuse in China.

Organic Ferroelectric Vortex-Antivortex Domain Structure

Organic ferroelectrics are attracting tremendous interest because of their mechanical flexibility, ease of fabrication, and low acoustical impedance. Although great advances have been made in recent years, topological defects such as vortices remain relatively unexplored in the organic ferroelectric system. Here, from [quinuclidinium]ReO₄ ([Q]ReO₄), we applied the molecular design strategy of H/F substitution to successfully synthesize the organic ferroelectric [4-fluoroquinuclidinium]ReO₄ ([4-F-Q]ReO₄). Through H/F substitution, the Curie temperature and spontaneous polarization are respectively increased from 367 K and 5.83 μC/cm² in [Q]ReO₄ to 466 K and 11.37 μC/cm² in [4-F-Q]ReO₄. Moreover, under mechanical stress fields, three kinds of stripelike domains with various polarization directions emerge to form a windmill-like domain pattern in the thin film of [4-F-Q]ReO₄, in which intriguing vortex-antivortex topological configurations can exist stably. This work provides an efficient strategy for optimizing the properties of organic ferroelectrics and exploring emergent phenomena.

[Application of a small drainage tube in transoral endoscopic thyroidectomy vestibular approach]

Objective: To examine the feasibility of small drain in transoral endoscopic thyroidectomy vestibular approach (TOETVA). Methods: A prospective research was performed in Department of Oncology Plastic Surgery/Head and Neck Surgery, Hunan Cancer Hospital, from October 2018 to March 2019. Totally 103 patients who met the inclusion and exclusion criteria, signed the operation agreement of TOETVA, had their surgery completed and followed-up over 6 months, were enrolled in analysis. A central venous catheter was used as a drain tube in all cases (outer diameter 1.7 mm, inner diameter 1.0 mm). Visual analogue scale (VAS) was applied for assessing pain scores during the first 24 hours after the operation. Vancouver scar scale (VSS) was used for assessing the scar left by the drainage. The drainage volume (minimum scale:10 ml, approximate read: 1 ml) was recorded every 2 hours during the first postoperative 12 hours, every 4 hours during 12 to 24 hours, every 8 hours during 24 to 48 hours, and once from 48 hours until extubation. The volume of drainage, the cumulative volume and the percentage of cumulative volume accounting for the total volume were calculated. The data of residual volume (subtract the cumulative volume from the total volume) in the postoperative 24, 32 and 40 hours were analyzed, and their upper one-side P(95) was calculated by percentile method. Results: There were 12 males and 91 females. The age was (36.6±9.7) years (range: 18 to 58 years). The intraoperative tube-inserting time was (10.1±2.6) minutes (range: 6 to 18 minutes). The pain score on the first day was 2.7±1.1 (range: 1 to 5). The extubation time was (2.7±0.5) days (range: 2 to 4 days). VSS scores in the postoperative 1(st) month and 6(th) month were 2.9±1.3 (range: 0 to 7) and 0(2)(M(Q(R))), respectively. The size of the scar was 0 (2.5) mm in the postoperative 6(th) month. Sixty-four patients had no visible scars. There were 5 patients who had postoperative drain-related complications (1 for air leakage, 1 for tube blockage, 3 for subcutaneous hydrop, 2 for regional infection), who were all cured after proper treatment. The total volume of drainage for 98 patients without postoperative drain-related complications was (80.1±12.2) ml (range: 58 to 131 ml). The cumulative drainage within 8 hours accounted for (53.8±4.2)% (range: 41.0% to 62.9%) of the total drainage. The volume of residual fluids in the postoperative 32 hours was estimated to (5.8±2.7) ml (range: 0 to 12 ml,P(95)=10.0 ml). Conclusions: The small drain tubecan be applied in TOETVA, providing a satisfied cosmetic appearance and a reliable drainage. The main exudation period of the wound is within 8 hours after the operation. If a residual volume less than 10 ml is considered to be self-absorbable, the shortest safe extubation point for 95% patients without drain-related complications should be 32 hours after the operation.

[A case of using profunda artery perforator flap as an intraoperative salvage for failed deep inferior epigastric artery perforator flap harvesting in autologous breast reconstruction]

On April 11, 2019, a 36-year-old female patient was admitted to Hunan Cancer Hospital. Five years after the modified radical mastectomy for right breast cancer, she planned to undergo scar releasing and reconstruction of right chest wall and free deep inferior epigastric artery perforator (DIEP) flap transfer, right breast reconstruction, and left breast mastopexy. The defect of right chest wall after scar resection was 18 cm×10 cm. During the operation, the vascular pedicle of DIEP flap was accidentally injured, then the profunda artery perforator flap in left inner thigh was designed for salvage. The size of the flap was 20 cm×11 cm, the thickness was 4.5 cm, the length of perforator vessel pedicle was 7.6 cm, and the weight of the flap was 360 g. The right breast defect was repaired with the transferred flap and the deep cavity was filled. The vascular pedicle of profunda artery was anastomosed with the proximal end of the right internal mammary artery. The blood supply of the flap was good during surgery. The left breast mastopexy was completed at the same time, and the donor site of thigh and abdomen was closed directly. The flap survived well and the donor site healed well after surgery. During the follow-up of 7 months post surgery, the appearance and function of thigh donor site were good, no obvious complications were found, and the reconstructed breast was smaller than the contralateral side. This case suggests that the profunda artery perforator flap could be a valuable option as an alternative for DIEP harvesting failure for autologous breast reconstruction.

Record Enhancement of Phase Transition Temperature Realized by H/F Substitution

A high transition temperature (T_c ) is essential for the practical application of ferroelectrics as electronic devices under extreme thermal conditions in the aerospace, automotive, and energy industries. In recent decades, the isotope effect and strain engineering are found to effectively modulate T_c ; however, these strategies are limited to certain systems. Developing simple, universal, and practical methods to improve T_c has become an imminent challenge for expanding the applications of ferroelectrics. Here, by adopting a molecular design strategy involving H/F substitution on an organic-inorganic hybrid perovskite (1-azabicyclo[2.2.1]heptane)CdCl₃ at a T_c of 190 K, the successful synthesis of a multiaxial, ferroelectric hybrid perovskite (4-fluoro-1-azabicyclo[2.2.1]heptane)CdCl₃ is reported, which demonstrates a large spontaneous polarization of 11.2 µC cm^-2 (greater than that of polyvinylidene difluoride) and a T_c of 419 K (greater than that of BaTiO₃ ). This temperature enhancement (229 K) is the largest reported for molecular ferroelectrics, far exceeding the reported enhancements induced by the isotope effect and other techniques. This pioneering technique provides an effective and universal method for improving T_c in ferroelectrics and represents an important step toward the development of high-performance ferroelectric technology.

[Selection and effects of flap/myocutaneous flap repair methods for the defect after perineum tumor resection]

Objective: To explore the selection and effects of flap/myocutaneous flap repair methods for the defect after perineum tumor resection. Methods: From January 2011 to February 2017, 31 patients with vulvar tumor who were admitted to Hunan Cancer Hospital underwent repair of wound after tumor resection with various flaps/myocutaneous flaps. The patients were composed of 5 males and 26 females, aged 39-76 years, with 27 vulvar cancer and 4 Paget's disease in primary diseases. The size of defects after vulvar tumor radical resection ranged from 8.0 cm×4.5 cm to 27.5 cm×24.0 cm. According to the theory of perforasome, the defects were repaired by the external pudendal artery perforator flap, deep inferior epigastric artery perforator flap, rectus abdominis myocutaneous flap, anterolateral thigh flap, internal pudendal artery perforator flap, gracilis myocutaneous flap, and profunda artery perforator flap based on the specific size and location of perineum and groin where the defect was located. According to the blood supply zone of flap, totally 17 local translocation flaps, 18 axial flaps/myocutaneous flaps, and 7 V-Y advancement flaps were resected, with an area of 7.0 cm×4.0 cm to 21.0 cm×13.0 cm. All the flaps/myocutaneous flaps were transferred in pedicled fashion, and the donor sites were closed without tension. The number of flaps/myocutaneous flaps, wound closure, flaps/myocutaneous flaps survival, and follow-up were observed and recorded. Results: Altogether 42 flaps/myocutaneous flaps were harvested in 31 patients. Two flaps/myocutaneous flaps were used in 11 cases for large circular defect repair. All the defects achieved tension-free primary closure. The blood supply of 32 flaps/myocutaneous flaps was good, while insufficient blood supply was noted in the other 10 flaps/myocutaneous flaps. Seventeen flaps/myocutaneous flaps survived smoothly. Wound dehiscence occurred in 5 flaps/myocutaneous flaps 8 to 14 days postoperatively, which was healed with dressing change. Temporary congestion was noted in 7 flaps/myocutaneous flaps 2 to 5 days postoperatively, which recovered without special treatment. Three flaps/myocutaneous flaps had infection 7 to 15 days postoperatively, two of which recovered after dressing change, while the other one had partial necrosis and received debridement and direct closure. Two flaps/myocutaneous flaps were totally necrotic 8 to 15 days postoperatively, which were repaired with pedicled rectus abdominis myocutaneous flap after debridement. Seven flaps/myocutaneous flaps had partial necrosis 7 to 20 days postoperatively and were healed after dressing change. Twenty-four patients were followed up for 9-38 months. The color of flaps/myocutaneous flaps was similar to that of the surrounding skin, the shape of vulva was natural, the movement of hip joint was not limited, the function of micturition and defecation was not affected, and tumor recurrence was noted in 3 patients. Conclusions: For the complicated large defect after perineum tumor resection, the flexible application of different forms of flaps/myocutaneous flaps to repair according to different areas regains the appearance and function. However, there are many complications, so it is necessary to further strengthen the postoperative care.

[Anatomical classification and application of chimeric myocutaneous medial thigh perforator flap in head and neck reconstruction]

Objective: To explore the anatomical classification and application of chimeric myocutaneous medial thigh perforator (MTP) flap in head and neck reconstruction. Methods: From September 2015 to December 2018, the clinical data of 74 patients (62 males and 12 females, age ranging from 31 to 69 years, with a mean age of 50.2 years) with oral tumor, who underwent radical resection in Hunan Cancer Hospital, including 39 cases of tongue carcinoma, 24 cases of gingival carcinoma and 11 cases of buccal cancer, 26 cases of stage T4N1M0, 22 cases of stage T4N0M0,15 cases of stage T3N1M0, and 11 cases of stage T3N2M0 were retrospectively analyzed in this work.The arteries and the veins contributing to MTP were anastomosed respectively with superior thyroid arteries, while the venae comitans were anastomosed with superior thyroid venae veins or internal jugular venae vein. The size of soft tissue defect, the length, width and thickness of free medial thigh flap, the length and source of vascular pedicle were recorded. The flap survival, functional status and donor area recovery were observed. Results: The postoperative defects in size ranged from 4.0 cm×3.5 cm to 9.0 cm×5.5 cm, which were reconstructed by free chimeric myocutaneous MTP flaps. The mean length of MTP flaps was (12.5±0.4) cm, the mean width was (7.2±0.4) cm, the mean thickness was (3.5±0.2) cm. The mean pedicle length was (8.6±0.4) cm. The perforators existed consistently in all cases, and the vascular origins were classified into 6 types. There were 4 cases (5.4%) of the perforating branches originating from femoral artery between the medial femoris and the adductor longus, 6 cases (8.1%) of the perforating branches of the profunda femoral artery from the adductor longus, 16 cases (21.6%) of the perforating branches of the profunda femoral artery from the gracilis, 9 cases (12.2%) of the perforating branches of the profunda femoral artery between the gracilis and the adductor longus, 29 cases (39.2%) of the perforating branches of the profunda femoral artery from the adductor longus, and 10 cases (13.5%) of branches of the profunda femoral artery from the semimembranous muscle. All 74 flaps survived uneventfully. The donor sites and recipient sites were closed directly in all cases. All patients were followed up for 12-36 months with satisfied esthetic and functional results. Only linear scars were left in the donor sites, and the thigh function was not affected. Local recurrence happened in 4 cases, which were treated with radical resection and the left defects were reconstructed with pedicled pectoral major myocutaneous flaps. Conclusion: The chimeric myocutaneous MTP flap has good color match and texture, with abundant tissue, and consistent blood supply, and it can be harvested in various forms while leaving minimal morbidity at donor site, being an idea choice for reconstruction after surgery of oral cancer.

[Hepatotoxicity associated with tumor immune checkpoint inhibitors]

Although tumor immune checkpoint inhibitors therapy brings survival benefits to cancer patients, it also faces many challenges, such as the occurrence of immune-mediated hepatotoxicity. Therefore, an in-depth understanding of the conditions, possible mechanisms, and risk factors that cause liver injury during the treatment of tumor immune checkpoint inhibitors will facilitate better clinical management.

Observation of Vortex Domains in a Two-Dimensional Lead Iodide Perovskite Ferroelectric

Topological defects, such as vortices and skyrmions, provide a wealth of splendid possibilities for new nanoscale devices because of their marvelous electronic, magnetic, and mechanical behaviors. Recently, great advances have been made in the study of the ferroelectric vortex in conventional perovskite oxides, such as BaTiO₃ and BiFeO₃. Despite extensive interest, however, no intriguing ferroelectric vortex structures have yet been found in organic-inorganic hybrid perovskites (OIHPs), which are desirable for their mechanical flexibility, ease of fabrication, and low acoustical impedance. We observed the robust vortex-antivortex topological configurations in a two-dimensional (2D) layered OIHP ferroelectric (4,4-DFPD)₂PbI₄ (4,4-DFPD is 4,4-difluoropiperidinium). This provides future directions for the study of perovskites and makes it a promising alternative for nanoscale ferroelectric devices in medical, micromechanical, and biomechanical applications.

An Above-Room-Temperature Molecular Ferroelectric: [Cyclopentylammonium]2CdBr4

Molecular ferroelectrics as alternatives to the conventional inorganic ferroelectrics have been greatly developed in past decades; many of these have been discovered and designed through various chemical means due to their structural adjustability. However, it is still a huge challenge to obtain high (above room temperature) Curie temperature (T_c) molecular ferroelectrics to meet the application requirements. Here, we present a new organic-inorganic hybrid molecular ferroelectric, [cyclopentylammonium]₂CdBr₄ (1), showing a moderate above-room-temperature T_c of 340.3 K. The mechanism of the ferroelectric phase transition from Pnam to Pna2₁ in 1 is ascribed to the order-disorder transition of both the organic cations and inorganic anions, affording a spontaneous polarization of 0.57 μC/cm² for the ferroelectric phase. Using piezoresponse force microscopy (PFM), we clearly observed the antiparallel 180° stripe domains and realized the polarization switching, unambiguously establishing the existence of room-temperature ferroelectricity in the thin film. These attributes make it attractive for use in flexible devices, soft robotics, biomedical devices, and other applications.

Two-Dimensional Layered Perovskite Ferroelectric with Giant Piezoelectric Voltage Coefficient

Piezoelectric sensors that can work under various conditions with superior performance are highly desirable with the arrival of the Internet of Things. For practical applications, a large piezoelectric voltage coefficient g and a high Curie temperature T_c are critical to the performance of piezoelectric sensors. Here, we report a two-dimensional perovskite ferroelectric (4-aminotetrahydropyran)₂PbBr₄ [(ATHP)₂PbBr₄] with a saturated polarization of 5.6 μC cm^-2, high T_c of 503 K [above that of BaTiO₃ (BTO, 393 K)], and extremely large g₃₃ of 660.3 × 10^-3 V m N^-1 [much beyond that of Pb(Zr,Ti)O₃ (PZT) ceramics (20 to 40 × 10^-3 V m N^-1), more than 2 times higher than that of poly(vinylidene fluoride) (PVDF, about 286.7 × 10^-3 V m N^-1)]. Combined with the advantages of molecular ferroelectrics, such as light weight, easy and environmentally friendly processing, and mechanical flexibility, (ATHP)₂PbBr₄ would be a competitive candidate for next-generation smart piezoelectric sensors in flexible devices, soft robotics, and biomedical devices.