Multifunctional MXene/PEDOT:PSS-Based Phase Change Organohydrogels for Electromagnetic Interference Shielding and Medium-Low Temperature Infrared Stealth

Electromagnetic interference (EMI) shielding and infrared stealth technologies are essential for military and civilian applications. However, it remains a significant challenge to integrate various functions efficiently into a material efficiently. Herein, a minimalist strategy to fabricate multifunctional phase change organohydrogels (PCOHs) was proposed, which were fabricated from polyacrylamide (PAM) organohydrogels, MXene/PEDOT:PSS hybrid fillers, and sodium sulfate decahydrate (Na2SO4·10H2O, SSD) via one-step photoinitiation strategies. PCOHs with a high enthalpy value (130.7 J/g) and encapsulation rate (98%) could adjust the temperature by triggering a phase change of SSD, which can hide infrared radiation to achieve medium-low temperature infrared stealth. In addition, the PCOH-based sensor has good strain sensing ability due to the incorporation of MXene/PEDOT:PSS and can precisely monitor human movement. Remarkably, benefiting from the electron conduction of the three-dimensional conductive network and the ion conduction of the hydrogel, the EMI shielding efficiency (k) of PCOHs can reach 99.99% even the filler content as low as 1.8 wt %. Additionally, EMI shielding, infrared stealth, and sensing-integrated PCOHs can be adhered to arbitrary targets due to their excellent flexibility and adaptability. This work offers a promising pathway for fabricating multifunctional phase change materials, which show great application prospects in military and civilian fields.

Epicoccanes A-D, Four Oxidative Dimers of Pyrogallol Analogues from Epicoccum nigrum

Epicoccanes A-D (1-4) are four novel metabolites of an endophytic fungus Epicoccum nigrum. Their distinct unprecedented structures are hypothesized as oxidative dimers of pyrogallol analogues. Compounds 1 and 2 possess a novel spirobicyclo[3.2.1]octane-6,1'-cyclopentane or -cyclohexane core skeleton. Compound 3 is of a unique cage-like pentacyclic system, which unusually contained three continuous spiro-carbons. Compound 4 is a highly rearranged dimer with five contiguous chiral centers. The absolute structures of 1 and 2 were deduced by electronic circular dichroism (ECD) calculations, and those of 3 and 4 were determined by X-ray crystallography. Compounds 1 and 4 showed potential antiliver fibrosis activity.

Ultraflexible PEDOT:PSS/Helical Carbon Nanotubes Film for All-in-One Photothermoelectric Conversion

Photothermoelectric (PTE) conversion can achieve the recovery of low-quality light or heat efficiently. Much effort has been devoted to the exploitation of the inorganic heterogeneous asynchronous (separate) PTE conversion system. Here, a full organic PTE film with a pseudobilayer architecture (PBA) according to the homogeneous synchronous (all-in-one) PTE conversion hypothesis was prepared via successive drop-casting a PEDOT:PSS/helical carbon nanotube (HCNT) mixture and PEDOT:PSS onto a vacuum ultraviolet treated substrate. Our results prove that the heptagon-pentagon pairs embedded in HCNTs promote a denser arrangement of the molecular chains of PEDOT, which enhances the crystallinity and affects the thermoelectric properties. The weak connection and hollow structure of HCNTs inhibit the dissipation of heat, and the zT value of the film reaches over 0.01. The PBA film shows better photothermal conversion performance than a neat PEDOT:PSS film and stably generates a temperature difference of over 25.68 °C without external cooling. A flexible PTE chip demo was manufactured, and the ideal open-circuit voltage (simulated via COMSOL) of that reaches over 1.5 mV under weak NIR stimulation (83.12 mW/cm2), which is the best value reported for an organic all-in-one PTE device, and the real maximum output power reaches 2.55 nW (166.01 mW/cm2). The chip has incredible ultraflexibility, and its inner resistance changes less than 1.42% after 10000 bending cycles and displays ultrahigh stability (similarity >90%) in a continuous periodic output. Our work fills the deficit of homogeneous synchronous PTE research for a PEDOT:PSS composite and is a preliminary attempt in an ultraflexible integrated all-in-one PTE chip design.

Fabricating High-Thermal-Conductivity, High-Strength, and High-Toughness Polylactic Acid-Based Blend Composites via Constructing Multioriented Microstructures

The massive accumulation of plastic waste has caused a serious negative impact on the human living environment. Replacing traditional petroleum-based polymers with biobased and biodegradable poly(l-lactic acid) (PLLA) is considered an effective way to solve this problem. However, it is still a great challenge to manufacture PLLA-based composites with high thermal conductivity and excellent mechanical properties via tailoring the microstructures of the blend composites. In the present work, a melt extrusion-stretching method is utilized to fabricate biodegradable PLLA/poly(butylene adipate-co-butylene terephthalate)/carbon nanofiber (PLLA/PBAT/CNF) blend composites. It is found that the incorporation of the extensional flow field induces the formation of multioriented microstructures in the composites, including the oriented PLLA molecular chains, elongated PBAT dispersed phase, and oriented CNFs, which synergistically improve the thermal conductivity and mechanical properties of the blend composites. At a CNF content of 10 wt %, the in-plane thermal conductivity, tensile strength, and elongation at break of the blend composite reach 1.53 Wm^-1 K^-1, 66.8 MPa, and 56.5%, respectively, which increased by 31.9, 73.5, and 874.1% compared with those of the conventionally hot-compressed sample (1.16 Wm^-1 K^-1, 38.5 MPa, and 5.8%, respectively). The main mechanism for the improved thermal conductivity is that the multioriented structure promotes the formation of a CNF thermal conductive network in the composites. The strengthening mechanism is attributed to the orientation of both PLLA molecular chains and CNFs in the stretching direction, restricting the movement of PLLA molecular segments around CNFs, and the toughening mechanism is due to the transformation of PLLA molecular chains from low-energy gt conformers to high-energy gg conformers induced by extensional flow field. More interestingly, after the extrusion-stretched samples are annealed, the oriented PLLA molecular chains form oriented crystal structures such as extended-chain lamellae, common "Shish-kebabs," and hybrid Shish-kebabs, which further enhance the thermal conductivity and heat resistance of the samples. This work reveals the effects of the orientation of the matrix molecular chains and crystallites on the thermal conductivity and mechanical properties of composites and provides a new way to prepare high-performance PLLA-based composites with high thermal conductivity, excellent mechanical properties, and high heat resistance.

Multifunctional Phase Change Composites Based on Elastic MXene/Silver Nanowire Sponges for Excellent Thermal/Solar/Electric Energy Storage, Shape Memory, and Adjustable Electromagnetic Interference Shielding Functions

Multifunctional phase change materials (PCMs) are highly desirable for the thermal management of miniaturized and integrated electronic devices. However, the development of flexible PCMs possessing heat energy storage, shape memory, and adjustable electromagnetic interference (EMI) shielding properties under complex conditions remains a challenge. Herein, the multifunctional PCM composites were prepared by encapsulating poly(ethylene glycol) (PEG) into porous MXene/silver nanowire (AgNW) hybrid sponges by vacuum impregnation. Melamine foams (MFs) were chosen as a template to coat with MXene/AgNW (MA) to construct a continuous electrical/thermal conductive network. The MF@MA/PEG composites showed a high latent heat (141.3 J/g), high dimension retention ratio (96.8%), good electrical conductivity (75.3 S/m), and largely enhanced thermal conductivity (2.6 times of MF/PEG). Moreover, by triggering the phase change of the PEG, the sponges displayed a significant photoinduced shape memory function with a high shape fixation ratio (∼100%) and recovery ratio (∼100%). Interestingly, the EMI shielding effectiveness (SE) can be adjusted from 12.4 to 30.5 dB by a facile compression-recovery process based on shape memory properties. Furthermore, a finite element simulation was conducted to emphasize the advantage of the MF@MA/PEG composites in the thermal management of chips. Such flexible PCM composites with high latent heat storage, light-actuated shape memory, and adjustable EMI shielding functions exhibit great potential as smart thermal management materials in military and aerospace applications.

Polypyrrole/Helical Carbon Nanotube Composite with Marvelous Photothermoelectric Performance for Longevous and Intelligent Internet of Things Application

Helical carbon nanotube (HCNT) is a vital member of carbon nanomaterials, but little effort was devoted to explore its unique characteristics and applications during the past few decades. Here, we report an organic thermoelectric composite with an excellent photothermoelectric (PTE) effect by conformally wrapping polypyrrole (PPy) on the intricate surface of HCNTs, which have been confirmed to have remarkable near-infrared (NIR) photothermal conversion capability and ultralow heat transportation characteristics. The results indicate that with the increasing HCNT content, PPy shell thickness reduces and exhibits denser as well as partial orientation, while the inter-ring angle slowly decreases and the bipolaron becomes dominant in carrier composition gradually. Consequently, the Seebeck coefficient increases monotonically, whereas the electrical conductivity remains nearly invariant. The final composite combines the benign thermoelectric properties, excellent photothermal response performance, and the lowest thermal conductivity of the carbon-based thermoelectric composite yet reported (0.064 W m^-1 K^-1). A single strip NIR light-stimulated adjustable delay switch was designed and fabricated, with the open-circuit voltage and short-circuit current under a 400 mW cm^-2 NIR-stimulated approach to 720 μV and 62 nA with the discrepancy of consecutive periodic output signals less than 4.2%, exhibiting incredible stability and reliability and demonstrating the highest output voltage of a single strip among the reported organic PTE composite at room temperature. Our work fills in a gap of HCNT research, which hitherto existed in the PTE and thermoelectric field.

Melamine foam and cellulose nanofiber co-mediated assembly of graphene nanoplatelets to construct three-dimensional networks towards advanced phase change materials

Organic phase change materials (OPCMs) play a great role in energy management owing to their large phase change enthalpy, but their intrinsic low thermal conductivity (TC) and bad encapsulation severely restrict their applications. To overcome these problems, we developed a novel but feasible method to fabricate a graphene nanoplatelet (GNP) aerogel with compact and oriented stacking in-plane walls and many through-plane bridges via melamine foam (MF) and cellulose nanofiber (CNF) co-mediated assembly of GNPs. After impregnating paraffin wax (PW), the composite PCMs exhibit a high TC of 1.42 W m^-1 K^-1 at only a GNP content of 4.1 wt%, increasing by 407% compared with pure PW, and simultaneously nearly no reduction of the phase change enthalpy of PW. Meanwhile, this kind of composite PCM can not only show excellent light-to-thermal and electric-to-thermal transition ability, but also be applied in delay switch devices with satisfactory results.

Constructing reduced graphene oxide/boron nitride frameworks in melamine foam towards synthesizing phase change materials applied in thermal management of microelectronic devices

Phase change materials (PCMs) exhibit wide application prospects in many fields related to energy utilization and management and attract increasing interest. In this work, through the graphene oxide (GO)-assisted dispersion technology, GO/boron nitride (BN) nanosheets were incorporated into melamine foam and successfully deposited on the surface of the foam framework after hydrothermal reaction. Through the following freeze-drying and carbonization treatment, the composite MF/rGO/BN aerogels were obtained with integrated hybrid rGO/BN frameworks. The composite PCMs were prepared through encapsulating polyethylene glycol (PEG) within the hybrid aerogels. The encapsulation stability and thermal properties of the composite PCMs were systematically investigated. The composite PCM sample containing the highest content of rGO/BN exhibited excellent encapsulation stability, high thermal conductivity (up to 0.79 W m^-1 K^-1), high phase change enthalpy (160.7 J g^-1) with the retention of 90.8% of the pure PEG, and excellent chemical and thermal stability. Further results clearly showed that the composite PCMs had excellent light-to-heat energy transition ability and could be used as a thermal management component to suppress the overheating of devices during the operation process, or to supply energy for thermoelectric devices under emergency conditions to ensure a continuous power supply sustained for a certain time until the safeguard procedures are adopted.

Achieving high performance poly(vinylidene fluoride) dielectric composites via in situ polymerization of polypyrrole nanoparticles on hydroxylated BaTiO3 particles

PPy@BTOH composite particles with a ‘mulberry-like’ structure are fabricated to prepare dielectric composites with excellent comprehensive dielectric properties.

Polymer dielectric composites have widespread applications in many fields ranging from energy storage, microelectronic devices, and sensors to power driven systems, etc. and attract much attention of researchers. However, it is still challenging to prepare advanced polymer dielectric composites with a high dielectric constant (ε′), low dielectric loss (tan δ) and simultaneously high breakdown strength (E_bd). In this work, conductive polypyrrole (PPy) nanoparticles were in situ synthesized in a reaction system containing the common barium titanate (BaTiO₃, BT) or hydroxylated BaTiO₃ (BTOH) particles, and then the PPy@BT and PPy@BTOH composite particles were incorporated into poly(vinylidene fluoride) (PVDF) to prepare the composites. The morphologies and microstructures of the PPy@BT and PPy@BTOH composite particles and the corresponding PVDF composites were comparatively investigated. The results showed that the PPy@BTOH composite particles had a ‘mulberry’-like morphology with a rough surface and the self-assembled structure could be maintained in the PVDF composites, which was apparently different from the PVDF/PPy@BT composites, in which most of the PPy nanoparticles dissociatively dispersed in the PVDF matrix. Electrical conductivity measurements showed that at high particle content (≥20 wt%), the PPy@BTOH composite particles endowed the composites with lower electrical conductivity compared with the PPy@BT composite particles. Dielectric property measurements showed that the ‘mulberry’-like PPy@BTOH composite particles endowed the PVDF composites with extremely high ε′, ultralow tan δ and high E_bd compared with the PVDF/PPy@BT composites with dissociatively dispersed PPy nanoparticles and BaTiO₃ particles. The polarization and loss mechanisms of the composites were then proposed based on the morphologies and the microstructures of the composites. This work provides an alternative way to fabricate functional dielectric particles through trace functional groups inducing in situ polymerization of conductive polymers, and these particles can be used to fabricate advanced dielectric composites.

Melamine Foam-Supported Form-Stable Phase Change Materials with Simultaneous Thermal Energy Storage and Shape Memory Properties for Thermal Management of Electronic Devices

Paraffin wax (PW) is widely used as a phase change material (PCM) in the thermal energy storage field, whereas the leakage and strong rigidity of PW have hindered its practical applications. In this work, binary melamine foam (MF)/PW blends with simultaneous thermal energy storage and shape memory properties were prepared through vacuum impregnation. Herein, PW performs as a latent heat storage material and as a switching phase for shape fixation and MF serves as a supporting material to prevent the leakage and as a permanent phase for shape recovery. Due to the light weight and super-elasticity of MF, the MF/PW PCMs possess not only good encapsulation ability and a high latent heat, but also excellent shape-fixing and recovery properties (shape-fixing and recovery ratios are about 100%). Besides, the MF/PW PCMs can be fabricated into arbitrary shapes using MF as a template, and they exhibit excellent shape memory cyclic performance and thermal reliability. A temperature-sensitive and temperature-controlled deployable panel is further established, which can be installed in the electronic device and used for temperature protection. With high thermal energy storage capability, excellent shape memory properties, shape designability, and stable cycling reliability, this multifunctional MF/PW PCM shows a promising application in thermal energy management systems.

Electrospun Fibrous Membranes with Dual-Scaled Porous Structure: Super Hydrophobicity, Super Lipophilicity, Excellent Water Adhesion, and Anti-Icing for Highly Efficient Oil Adsorption/Separation

Developing highly efficient and multifunctional membranes toward oil adsorption and oil/water separation is of significance in oily wastewater treatment. Herein, a novel electrospun composite membrane with dual-scaled porous structure and nanoraised structure on each fiber was fabricated through electrospinning using biodegradable polylactide (PLA) and magnetic γ-Fe₂O₃ nanoparticles. The PLA/γ-Fe₂O₃ composite membranes show high porosity (>90%), superhydrophobic and superlipophilic performances with CH₂I₂ contact angle of 0°, good water adhesion ability like water droplets on a petal surface, excellent anti-icing performance, and good mechanical properties with a tensile strength of 1.31 MPa and a tensile modulus of 11.65 MPa. The superlipophilicity and dual-scaled porous structure endow the composite membranes with ultrahigh oil adsorption capacity up to 268.6 g/g toward motor oil. Furthermore, the composite membranes also show high oil permeation flux up to 2925 L/m² h under the force of gravity. Even for oil/water emulsion, the composite membranes have high separation efficiency. We expect that the PLA/γ-Fe₂O₃ composite membranes can be used in oily wastewater treatment under various conditions through one-off adsorption or continuous oil/water separation, especially under low environmental temperature condition.

One-step fabrication of functionalized poly(l-lactide) porous fibers by electrospinning and the adsorption/separation abilities

In this work, novel functionalized poly(l-lactide) (F-PLLA) porous fibers were fabricated through electrospinning using the PLLA/methylene chloride (CH₂Cl₂)/N,N-dimethylformamide (DMF) solution containing diethylenetriamine (DETA) and γ-aminopropyltriethoxysilane (KH-550). The effects of PLLA, DETA and KH-550 contents on the morphologies of the electrospun fibers were systematically investigated, and the results showed that at PLLA, DETA and KH-550 contents of 20% w/v, 2 wt% and 3 wt%, respectively, the electrospun F-PLLA fibers exhibited the homogeneous distribution of fiber diameters and the homogeneous porous structure on the fiber surface. Nitrogen-containing groups were successfully introduced to the electrospun fibers, which induced the great improvement of the hydrophilicity of the membrane surface. Adsorption measurements showed that the electrospun F-PLLA membrane had good adsorption ability toward Congo red (CR), and the adsorption capacity at room temperature was enhanced in 16 times compared with the common PLLA fiber membrane, and the maximum adsorption capacity was 135.7 mg g^-1. Furthermore, the adsorption behavior could be well described by the pseudo second-order model. Oil/water separating measurements showed that the electrospun F-PLLA membrane exhibited high separation efficiency and the maximum water fluxes were 2018 and 1861 L m^-2  h^-1 in separating non-emulsified and emulsified oil/water system under atmospheric pressure, respectively.

Bio-inspired functionalization of microcrystalline cellulose aerogel with high adsorption performance toward dyes

As one of the materials from natural resources, the functionalization and application of cellulose attract increasing concerns. In this work, we reported a facile method to prepare the bio-inspired functionalization of microcrystalline cellulose (MCC) aerogel through polydopamine (PDA) coating, which was realized via the self-polymerization of dopamine in the MCC/LiBr solution followed by the freeze-drying technology. The morphological characterization showed that the pore morphologies of the compounded aerogel were influenced by the content of PDA. Adsorption measurements toward methylene blue (MB) showed that the compounded aerogel had high adsorption ability. Moreover, the compounded MCC/PDA aerogel exhibited excellent adsorption selectivity and it exhibited high efficiency to remove MB from different solutions, such as the mixed solution with anionic dyestuffs, the mixed solution with cationic dyestuffs and the mixed solution with common salt (NaCl). The high adsorption ability and excellent adsorption selectivity endows the compounded MCC/PDA aerogel with great potential applications in wastewater treatment.

[Advance of the use of auricular othosis in congenital ear deformities]

Congenital ear deformities are common diseases in infants and can be effectively corrected by ear molding. However, the current knowledge about the auricular othosis is still insufficiency. As the new type of ear correction system has been produced, non-surgical correction of ear deformities is increasingly popular. To promote and standardize its clinical application, here, we reviewed the advanced publications associated with neonatal ear molding, focusing on auricular deformities classification, incidence rate, self-healing rate, as well as pathological mechanism. The review also included various auricular othosis materials, treatment opportunity, cure rate and complications.

Fabrication of high-efficiency and low-stray-light grating by inductively coupled plasma(ICP) etching-polishing method

Gratings with stray light of 4.99 × 10^-7-5.67 × 10^-7 and efficiency of 93%-95% in a wavelength range of 1592 nm-1632 nm on Si-surface-modification SiC, fused silica and BK7 have been fabricated by the method of ICP etching-polishing. The CHF₃ and SF₆ plasma were used to etch a preliminary grating profile. Ar and O₂ plasma with low energy were then used to polish the grating to acquire low surface roughness and groove profiles closer to the ideal profiles. The morphologies of the gratings were characterized by AFM. The efficiencies and stray light were measured quantitatively by self-developed equipment. These results show that the ICP etching-polishing method is a promising candidate for production of good quality gratings into common optical materials.

Effect of epristeride on the expression of IGF-1 and TGF-beta receptors in androgen-induced castrated rat prostate

The development of benign prostatic hyperplasia (BPH) is an androgen-dependent process that may be mediated by a number of locally produced growth factors. Among them, insulin-like growth factor 1 (IGF-1) and transforming growth factor beta (TGF beta) are thought important in regulating prostate growth and homeostasis, and their expression undergoes changes in proliferative prostatic disease. Epristeride, a 5 alpha-reductase inhibitor, is an effective drug in the treatment of BPH, inducing regressive changes in the prostate. This study was designed to assess the effects of epristeride on expression of these two factors at mRNA and protein levels in castrated rats maintained with exogenous testosterone. Epristeride treatment caused significant reduction in ventral prostate weight in a dose-dependent manner. There was a positive correlation between IGF-1 mRNA expression and ventral prostate weight and an inverse correlation between TGF-beta 1 mRNA expression and ventral prostate weight. Immunohistochemistry showed strong IGF-1 receptor immunoreactivity in the prostatic epithelial cells of untreated animals. In situ hybridization demonstrated high levels of IGF-1 mRNA expression both in the prostatic stromal and epithelial cells of untreated rats. In treated rats, both IGF-1 receptor protein and IGF-1 mRNA levels decreased significantly, and IGF-1 mRNA was mainly expressed in prostatic stromal cells. Weak expression of TGF beta receptors at the protein level and TGF beta at the mRNA level were found in the prostatic hyperplastic epithelial cells of untreated rats. In treated animals, intense T beta RII immunoreactivity was observed in epithelial cells, and a higher level of TGF beta mRNA was observed in both epithelial cells and stromal cells compared with control animals. In our opinion, the effect of epristeride on rat prostatic atrophy might be mediated via local growth factor(s).

Reversible long-term toxicity of epristeride in beagle dogs

Epristeride (17beta-N-t-butylcarboxamide-androst-3, 5-diene-3-carboxylic acid) is an uncompetitive inhibitor of steroid 5alpha-reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT), and has been shown to retard the growth of hyperplastic prostates. The objective of the current investigation was to research the toxic effects of epristeride and to demonstrate its reversible. In the experiment, 18 beagle dogs (male, about 6 months old) were used and divided into six groups, with each group containing three dogs. Groups A and B were placebo-treated for 180 and 240 days, Groups C and D were treated with 10 and 100 mg/kg epristeride for 180 days, and Groups E and F were treated with 10 and 100 mg/kg epristeride for 180 days and then were placebo-treated for 60 days (total 240 days), respectively. Routine analyses were performed at the 1st, 30th, 90th, 180th, and 240th days, and the dogs were autopsied at the 180th or 240th day for systemic examination and measured for relative DNA content in single prostatic epithelial cells. Each prostate was fixed with 4% Formalin, embedded in paraffin, sectioned at 6 micron, and immunohistochemically stained for assaying the relative content (transmittance) of prostatic specific antigen (PSA) and DHT (%) with a microspectrophotometer at 650-nm wavelength. The results were that 180 days of toxicity with epristeride (100 mg/kg) on interstitial cells of testes and DNA in prostatic epithelial cells couldn't reverse during 60 days of convalescence and that the DHT and PSA levels in the gland, the volume of the gland, glandular epithelial cell height, and acinar luminal area could reverse to normal during the same convalescence. To our knowledge this is the first study documenting the toxicity of epristeride. It is necessary to further study the molecular and clinical toxicity of epristeride.

[Intraoperative lymph nodes dissection guided by preoperative endoscopical injection of mitomycin C absorbed activated carbon (MMC-CH40) at pericancerous gastric mural in patients with gastric cancer]

22 patients with gastric cancer underwent preoperative endoscopical MMC-CH injection before radical resection. Lymph nodes resected in MMC-CH40 group averaged 47.0 vs. 28.1 in the control group (P < 0.05). Positive nodes were found 15 of 22 cases (68%) in MMC-CH40 group vs. 22 out of 26 cases (77%) in the control group (P > 0.05). Positive nodes totalled up to 166 of all 1033 dissected in the former (16%) vs. 162 of 730 (23%) in the latter (P < 0.01). Positive nodes found in 15 of 22 cases in MMC-CH40 group averaged 11.07 per lymph-node-metastasized patient vs. 7.36 in the control group (P < 0.01). The results showed that this procedure is of assistance to thorough dissection of lymph node during surgery.

[Lack of mutagenicity and teratogenicity of 16-methylene-17 alpha-acetoxy-19-norprogesterone]

16-Methylene-17 alpha-acetoxy-19-norprogesterone (ST-1435) is a new antifertility agent. ST-1435 silastic capsule was implanted sc in the nuchal region of rats on d 6 of gestation at 75, 300, and 600 mg.kg-1. The rats were killed on d 20. In comparison with the control, the treated groups showed no significant differences in maternal body weights, number of corpora lutea, and the development of embryos and fetuses. The number of dead fetuses decreased and live fetuses increased slightly. ST-1435 did not affect the frequency of micronucleated polychromatic erythrocytes, nor induce chromosomal aberrations in cultured CHL cells, or increase the revertants of Salmonella typhimurium TA97, TA98, TA100, and TA102 in Ames test. The results suggested that ST-1435 had neither teratogenicity nor mutagenicity.

[Effects of 10-hydroxycamptothecin on induced chromosome aberrations in Chinese hamster ovary cells and micronuclei in mouse bone marrow and fetal liver]

10-Hydroxycamptothecin (HC) is a new antitumor principle isolated from Camptotheca acuminata indigenous to China. The genetic toxicity of HC was assessed by mouse bone marrow and transplacental micronucleus test as well as Chinese hamster ovary cell chromosomal aberrations. All of these tests showed positive results. The highest rate of chromosomal aberrations was 83% at 0.125 microgram/ml for 48 h. The number of micronucleated polychromatic erythrocytes in bone marrow of mice was remarkably increased in 19.8% cells at 12.5 mg/kg for 24 h. The micronucleus formation was most often seen at 16 h after im HC in fetal liver and 24 h in maternal bone marrow. The peaks were 36 +/- 19 and 31 +/- 10%, respectively. The results from in vivo and in vitro suggest HC is a mutagen, furthermore, a transplacental mutagen in mouse.

[Gastroscopic mucosal biopsy and carbon ink injection marking for determination of resection line on the gastric wall in stomach cancer]

Gastroscopic mucosal biopsies and carbon ink injection marking were performed in 31 patients with gastric cancer before operation. The resection line of gastric wall was determined during operation according to the marked points. The method, dose, site, and opportunity of ink injection were studied. The results were: 1. None of these 31 patients had positive biopsies from cancer free areas. None of the resected specimens showed deep cancer infiltration beyond the site of carbon ink injection. This method is significant in recognizing the extent of intramucosal cancer infiltration; 2. None of the 31 patients marked by ink injection had residual cancer on the resected line whereas 8-10% of those unmarked had a positive margin. This result indicates that this method is significant in avoiding residual cancer on the resection line; and 3. Before surgery, the home-made carbon ink was satisfactory. The optimum dose for an ideal ink point was 0.05-0.1 ml/point which would give a marking of 0.5-1.5 cm in diameter on the serosa. The ink point was clearly shown on the anterior wall but less satisfactorily on the lesser curvature of the stomach. Injection performed as early as the fifth week before operation was valid.