Evaluating Tislelizumab, Lenvatinib, and FOLFOX4-HAIC as a Conversion Therapy for Unresectable Hepatocellular Carcinoma

Background and aims:Conversion therapy downstages tumors and renders patients with unresectable hepatocel-lular carcinoma(HCC)eligible for radical resection.This study aimed to evaluate the efficacy and safety of tislelizumab plus lenvatinib and hepatic artery infusion chemotherapy with oxaliplatin,fluorouracil,and leuco-vorin(FOLFOX4-HAIC)as a first-line conversion therapy.Methods:Clinical data from HCC patients who were treated with the triple therapy between April 2021 and April 2022 were retrospectively analyzed.The primary outcome included objective response rate(ORR),disease control rate(DCR),conversion resection rate(CRR),and treatment-related adverse events(TRAEs).Results:A total of 18 patients completed conversion therapy assessment,which ended on March 27,2023.The patients had a median age of 55.5(37–72)years,and 94.4%were male.According to mRECIST,tumor shrinkage was observed in all patients,with an ORR of 94.4%(17/18),a DCR of 94.4%(17/18),and a median time to response of 1.4(0.7–3.0)months.Successful conversion was observed in 61.1%(11/18)of patients(mRECIST).The CRR and pathological complete response were 38.9%(7/18)and 57.1%(4/7),respectively.The median progression-free survival(PFS)was 17.8 months,while median overall survival was not reached.The 6-and 9-month PFS rates were 83.3%and 66.7%,respectively.The most common TRAE(16/18 patients,88.9%)was an increase in aspartate aminotransferase levels.Conclusion:Tislelizumab combined with lenvatinib and FOLFOX4-HAIC achieved a high conversion rate and acceptable toxicity in patients with unresectable HCC,suggesting that this combination may represent a new conversion strategy for this population.

Defects as a factor limiting carrier mobility in WSe2： A spectroscopic investigation

The electrical performance of two-dimensional transition metal dichalcogenides （TMDs） is strongly affected by the number of structural defects. In this work, we provide an optical spectroscopic characterization approach to correlate the number of structural defects and the electrical performance of WSe2 devices. Low-temperature photoluminescence （PL） spectra of electron-beam-lithography- processed WSe2 exhibit a clear defect-induced PL emission due to excitons bound to defects, which would strongly degrade the electrical performance. By adopting an electron-beam-free transfer-electrode technique, we successfully prepared a backgated WSe2 device containing a limited amount of defects. A maximum hole mobility of approximately 200 cm2.V -1.s-1 was achieved because of the reduced scattering sources, which is the highest reported value for this type of device. This work provides not only a versatile and nondestructive method to monitor the defects in TMDs but also a new route to approach the room-temperature phonon-limited mobility in high-performance TMD devices.

Synergistic graphene/aluminum surface plasmon coupling for zinc oxide lasing improvement

Collective oscillations of free electrons generate plasmons on the surface of a material. A whispering-gallery microcavity effectively confines the light field on its surface based on the total reflection from its internal wall. When these two kinds of electromagnetic waves meet each other, the stimulated emissions from an individual ZnO microrod were enhanced more than 50-fold and the threshold was reduced after the whispering-gallery microcavity was coated with a monolayer of graphene and A1 nanoparticles. The improvement of the lasing performance was attributed to the synergistic energy coupling of the graphene/A1 surface plasmons with ZnO excitons. The lasing characteristics and the coupling mechanism were investigated systematically.

Realization of vertical and lateral van der Waals heterojunctions using two-dimensional layered organic semiconductors

Van der Waals （vdW） heterojunctions based on two-dimensional （2D） atomic crystals have been extensively studied in recent years. Herein, we show that both vertical and lateral vdW heterojunctions can be realized with layered molecular crystals using a two-step physical vapor transport （PVT） process. Both types of heterojunctions show clean and sharp interfaces without phase mixing under atomic force microscopy （AFM）. They also exhibit a strong interfacial built-in electric field similar to that of their inorganic counterparts. These heterojunctions have greater potential for device applications than individual materials. The lateral heterojunction （LHJ） devices show rectifying characteristics due to the asymmetric energy barrier for holes at the interface, while the vertical heterojunction （VHJ） devices behave like metal-insulator-semiconductor tunnel junctions, with pronounced negative differential conductance （NDC）. Our work extends the concept of vdW heterojunctions to molecular materials, which can be generalized to other layered organic semiconductors （OSCs） to obtain new device functionalities.

Probing the intrinsic optical quality of CVD grown MoS2

Optical emission efficiency of two-dimensional layered transition metal dichalcogenides （TMDs） is one of the most important parameters affecting their optoelectronic performance. The optimization of the growth parameters by chemical vapor deposition （CVD） to achieve optoelectronic-grade quality TMDs is, therefore, highly desirable. Here, we present a systematic photoluminescence （PL） spectroscopic approach to assess the intrinsic optical and crystalline quality of CVD grown MoS2 （CVD MoS2）. We propose the use of the intensity ratio between the PL measured in air and vacuum as an effective way to monitor the intrinsic optical quality of CVD MoS2. Low-temperature PL measurements are also used to evaluate the structural defects in MoS2, via defect-associated bound exciton emission, which well correlates with the field-effect carrier mobility of MoS2 grown at different temperatures. This work therefore provides a sensitive, noninvasive method to characterize the optical properties of TMDs, allowing the tuning of the growth parameters for the development of optoelectronic devices.

Investigation of multilayer domains in large-scale CVD monolayer graphene by optical imaging

CVD graphene is a promising candidate for optoelectronic applications due to its high quality and high yield.However,multi-layer domains could inevitably form at the nucleation centers during the growth.Here,we propose an optical imaging technique to precisely identify the multilayer domains and also the ratio of their coverage in large-scale CVD monolayer graphene.We have also shown that the stacking disorder in twisted bilayer graphene as well as the impurities on the graphene surface could be distinguished by optical imaging.Finally,we investigated the effects of bilayer domains on the optical and electrical properties of CVD graphene,and found that the carrier mobility of CVD graphene is seriously limited by scattering from bilayer domains.Our results could be useful for guiding future optoelectronic applications of large-scale CVD graphene.

A novel contact engineering method for transistors based on two-dimensional materials

Contact engineering is of critical importance for two-dimensional(2D)transition metal dichalcogenide(TMD)-based devices.However,there are only a few solutions to overcome this obstacle because of the complexity of the TMD-contact interface.In this work,we propose a novel method using a soft plasma treatment followed by the seamless deposition of a metal electrode to reduce the contact resistance of MoS_(2)field effect transistors(FETs).The treated FETs exhibit three times higher mobility than the control FETs without plasma treatment.The soft plasma treatment can remove the facial sulfur atoms and expose the middle Mo atoms so that they come into direct contact with the metal electrode,thus greatly improving the contact behavior.First-principles calculation is also performed to support the experimental results.Our potentially scalable strategy can be extended to the whole family of TMD based FETs to provide a possible route of device processsing technology for 2D device application.