Incidence and survival of second primary non-Hodgkin lymphoma: A Surveillance, Epidemiology, and End Results-based cohort study.

BACKGROUND: The aim of this study was to investigate patient survival and factors associated with survival in second primary non-Hodgkin lymphoma (NHL) compared with the first primary NHL. METHODS: The retrospective cohort study used data from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2014. Demographic characteristics, histological types, Ann Arbor stage, and treatment information were collected. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for factors associated with overall survival (OS) and cancer-specific survival (CSS) in the first and second primary NHLs. RESULTS: Of 318,168 cases followed for 5 years, 299,248 patients developed the first primary NHL and 18,920 patients developed the second primary NHL. This study identified a rising incidence of first and second primary NHL from 2000 to 2014. For the second primary NHL, the OS risk was higher when compared to the first primary NHL (HR: 1.13, 95% CI: 1.11 to 1.15, P <0.001). Risk factors that negatively affected OS in the first primary NHL included being male, over 40 years of age, certain marital statuses, specific histological types, and advanced disease stages. In contrast, being of White race and having histological types such as Follicular Lymphoma (FL), Marginal Zone Lymphoma (MZL), and mantle B-cell NHL were associated with better OS outcomes. Treatments like surgery, radiation therapy, and chemotherapy were associated with a lower risk of OS and CSS in the first primary NHL. For the second primary NHL, the detrimental risk factors were similar but also included being over the age of 60. Certain histological types showed a lower OS risk relative to diffuse Large B-cell Lymphoma (DLBCL). While surgery and chemotherapy were beneficial for OS, radiation therapy did not improve survival in second primary NHL cases. Notably, undergoing chemotherapy for the first primary cancer increased the OS risk in the second primary NHL, whereas surgery and radiation seemed to offer a protective effect against OS risk in the second primary NHL (all P <0.05). CONCLUSION: Our findings emphasize the need for tailored strategies in managing the second primary NHL, given the distinct survival patterns and risk factor profiles compared to the first primary NHL. Future research should aim to further elucidate these differences to improve prognosis and treatment approaches for second primary NHL patients.

PAQR3 facilitates the ferroptosis of diffuse large B-cell lymphoma via the regulation of LDLR-mediated PI3K/AKT pathway.

Progesterone and adiponectin receptor 3 (PAQR3) has been found to regulate tumor progression by mediating cell ferroptosis. However, whether PAQR3 mediates ferroptosis in diffuse large B-cell lymphoma (DLBCL) needs further investigation. The mRNA and protein levels of PAQR3 and low-density lipoprotein receptor (LDLR) were assessed by qRT-PCR and WB assays. Cell proliferation was detected by MTT assay and EdU assay. Shrunken mitochondria was counted under transmission electron microscope. Cell ferroptosis was evaluated by measuring the levels of malondialdehyde, reactive oxygen species, glutathione, Fe2+ , and the protein expression of ferroptosis-related markers. PAQR3 and LDLR interaction was confirmed by RIP assay and pull-down assay. Our study showed that PAQR3 was underexpressed, while LDLR was overexpressed in DLBCL tissues and cells. Functionally, PAQR3 overexpression or LDLR knockdown restrained DLBCL cell proliferation and enhanced ferroptosis. Mechanistically, PAQR3 reduced LDLR expression by inhibiting its mRNA stability. Meanwhile, LDLR overexpression reversed PAQR3-mediated the promoting on DLBCL cell ferroptosis, and LY294002 (PI3K/AKT inhibitor) eliminated the inhibiting effects of LDLR overexpression on DLBCL cell ferroptosis. Additionally, excessive PAQR3 reduced DLBCL tumor growth by enhancing tumor cell ferroptosis through LDLR-mediated PI3K/AKT pathway. In conclusion, our data suggested that PAQR3 restrained DLBCL progression by aggravating ferroptosis, which was achieved by inhibiting LDLR expression to repress PI3K/AKT pathway.

GCSTI: A Single-Cell Pseudotemporal Trajectory Inference Method Based on Graph Compression.

The single-cell pseudotemporal trajectory inference is an important way to explore the process of developmental changes within a cell. Due to the uneven rate of cell growth, changes in gene expression depend less on the time of data collection and more on a cell's "internal clock". To overcome the challenges of gene analysis, and replicate biological developmental processes, several strategies have been put forth. However, due to the size of single-cell datasets, locating relevant signposts usually necessitate clustering analysis or a sizable amount of priori information. To this end, we propose a novel single-cell pseudotemporal trajectory inference technique: GCSTI method, which is based on graph compression and doesn't rely on a priori knowledge or clustering procedures, can handle the trajectory inference problem for a large network in a stable and efficient manner. Additionally, we simultaneously improve the pseudotime defining method currently employed in this study in order to obtain more trustworthy and beneficial outcomes for trajectory inference. Finally, we validate the efficacy and stability of the GCSTI method using datasets from human skeletal muscle myogenic cells and four simulated datasets.

Revealing the key role of molecular packing on interface spin polarization at two-dimensional limit in spintronic devices.

Understanding spinterfaces between magnetic metals and organic semiconductors is essential to unlock the great potentials that organic materials host for spintronic applications. Although plenty of efforts have been devoted to studying organic spintronic devices, exploring the role of metal/molecule spinterfaces at two-dimensional limit remains challenging because of excessive disorders and traps at the interfaces. Here, we demonstrate atomically smooth metal/molecule interfaces through nondestructively transferring magnetic electrodes on epitaxial grown single-crystalline layered organic films. Using such high-quality interfaces, we investigate spin injection of spin-valve devices based on organic films of different layers, in which molecules are packed in different manners. We find that the measured magnetoresistance and the estimated spin polarization increase markedly for bilayer devices compared with their monolayer counterparts. These observations reveal the key role of molecular packing on spin polarization, which is supported by density functional theory calculations. Our findings provide promising routes toward designing spinterfaces for organic spintronic devices.

Sliding nanomechanical resonators.

The motion of a vibrating object is determined by the way it is held. This simple observation has long inspired string instrument makers to create new sounds by devising elegant string clamping mechanisms, whereby the distance between the clamping points is modulated as the string vibrates. At the nanoscale, the simplest way to emulate this principle would be to controllably make nanoresonators slide across their clamping points, which would effectively modulate their vibrating length. Here, we report measurements of flexural vibrations in nanomechanical resonators that reveal such a sliding motion. Surprisingly, the resonant frequency of vibrations draws a loop as a tuning gate voltage is cycled. This behavior indicates that sliding is accompanied by a delayed frequency response of the resonators, making their dynamics richer than that of resonators with fixed clamping points. Our work elucidates the dynamics of nanomechanical resonators with unconventional boundary conditions, and offers opportunities for studying friction at the nanoscale from resonant frequency measurements.

The impacts of urban land expansion on ecosystem services in Wuhan, China.

A clear understanding of the impacts of urban land expansion on ecosystem services is crucial for sustainable urban planning. Although various studies have shown that urban land expansion caused a degradation of ecosystem services, the relationship between the spatial variation of urban land expansion and ecosystem services still remains unclear. This study quantified the ecosystem services and urban land expansion indicators of Wuhan for 1990-2015 and analyzed the spatial and temporal variation characteristics of ecosystem service values (ESVs) and urban land expansion indicators. Using spatial autocorrelation analysis and linear regression, the quantitative and qualitative correlations between ecosystem services and urban land expansion indicators were explored. The total ESV of Wuhan decreased by 16.47%, representing a loss of 1636.19 million yuan. Areas with extremely low ESVs continuously expanded outward from the urban center. During 2010-2015, the urban land expansion area, intensity, damage weight, and distance peaked, which caused an enormous decrease of the total ESV. Negative correlations were found between urban land expansion and all ecosystem services; the correlation with food production was most significant, indicating that urban land expansion had the strongest impact on food production. The expansion area is the main factor causing the decline of each ecosystem service among urban land expansion indicators. This study presents the impact characteristics of urban land expansion on ecosystem services, and the results provide a reference for reasonable decision making in urban planning.

Graphene-Based Nanoelectromechanical Periodic Array with Tunable Frequency.

Phononic crystals (PnCs) have attracted much attention due to their great potential for dissipation engineering and propagation manipulation of phonons. Notably, the excellent electrical and mechanical properties of graphene make it a promising material for nanoelectromechanical resonators. Transferring a graphene flake to a prepatterned periodic mechanical structure enables the realization of a PnC with on-chip scale. Here, we demonstrate a nanoelectromechanical periodic array by anchoring a graphene membrane to a 9 × 9 array of standing nanopillars. The device exhibits a quasi-continuous frequency spectrum with resonance modes distributed from ∼120 MHz to ∼980 MHz. Moreover, the resonant frequencies of these modes can be electrically tuned by varying the voltage applied to the gate electrode sitting underneath. Simulations suggest that the observed band-like spectrum provides an experimental evidence for PnC formation. Our architecture has large fabrication flexibility, offering a promising platform for investigations on PnCs with electrical accessibility and tunability.

LINC00857 contributes to proliferation and lymphomagenesis by regulating miR-370-3p/CBX3 axis in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) remains to be a high aggressive and invasive malignancy with enigmatic etiology. Ectopic expression of long non-coding RNAs is widely involved in the progression of human cancers. We discovered that LINC00857 level was remarkably elevated in DLBCL tissues compared with non-tumor controls. High LINC00857 level predicts lower survival rate, more advanced tumor node metastasis and larger tumor size. LINC00857 overexpression promoted DLBCL cell proliferation and facilitated cell cycle as evidenced by elevated Cyclin D1 and proliferating cell nuclear antigen (PCNA) accompanying with reduced p21 level. LINC00857 overexpression also suppressed DLBCL cell apoptosis as evidenced by elevated Bcl-2 protein level, reduced Bax and cleaved caspase-3 protein levels. On the contrary, LINC00857 knockdown using short hairpin RNAs inhibited DLBCL cell proliferation yet induced cell apoptosis. LINC00857 knockdown also repressed tumor growth in vivo, concomitant with decreased Ki67 level. Besides, microRNA miR-370 was down-regulated in DLBCL tissues and served as a competitive endogenous RNA (ceRNA) target of LINC00857. We further validated that chromobox homolog 3 (CBX3) served as a downstream target gene of miR-370-3p. LINC00857 level was reversely correlated with miR-370-3p level yet positively correlated with CBX3 level. In addition, CBX3 overexpression alleviated the impact of LINC00857 knockdown on DLBCL cell survival. In conclusion, our findings indicated that LINC00857 contributes to DLBCL proliferation and lymphomagenesis through regulating miR-370-3p/CBX3 axis.

Tunable parametric amplification of a graphene nanomechanical resonator in the nonlinear regime.

Parametric amplification is widely used in nanoelectro-mechanical systems to enhance the transduced mechanical signals. Although parametric amplification has been studied in different mechanical resonator systems, the nonlinear dynamics involved receives less attention. Taking advantage of the excellent electrical and mechanical properties of graphene, we demonstrate electrical tunable parametric amplification using a doubly clamped graphene nanomechanical resonator. By applying external microwave pumping with twice the resonant frequency, we investigate parametric amplification in the nonlinear regime. We experimentally show that the extracted coefficient of the nonlinear Duffing force α and the nonlinear damping coefficient η vary as a function of external pumping power, indicating the influence of higher-order nonlinearity beyond the Duffing (∼x 3) and van der Pol (∼[Formula: see text]) types in our device. Even when the higher-order nonlinearity is involved, parametric amplification still can be achieved in the nonlinear regime. The parametric gain increases and shows a tendency of saturation with increasing external pumping power. Further, the parametric gain can be electrically tuned by the gate voltage with a maximum gain of 10.2 dB achieved at the gate voltage of 19 V. Our results will benefit studies on nonlinear dynamics, especially nonlinear damping in graphene nanomechanical resonators that has been debated in the community over past decade.

A Suspended Silicon Single-Hole Transistor as an Extremely Scaled Gigahertz Nanoelectromechanical Beam Resonator.

Suspended single-hole transistors (SHTs) can also serve as nanoelectromechanical resonators, providing an ideal platform for investigating interactions between mechanical vibrations and charge carriers. Demonstrating such a device in silicon (Si) is of particular interest, due to the strong piezoresistive effect of Si and potential applications in Si-based quantum computation. Here, a suspended Si SHT also acting as a nanoelectromechanical beam resonator is demonstrated. The resonant frequency and zero-point motion of the device are ≈3 GHz and 0.2 pm, respectively, reaching the best level among similar devices demonstrated with Si-containing materials. The mechanical vibration is transduced to electrical readout by the SHT. The signal transduction mechanism is dominated by the piezoresistive effect. A giant apparent effective piezoresistive gauge factor with strong correlation to single-hole tunneling is extracted in this device. The results show the great potential of the device in interfacing charge carriers with mechanical vibrations, as well as investigating potential quantum behavior of the vibration phonon mode.

Coherent phonon dynamics in spatially separated graphene mechanical resonators.

Vibrational modes in mechanical resonators provide a promising candidate to interface and manipulate classical and quantum information. The observation of coherent dynamics between distant mechanical resonators can be a key step toward scalable phonon-based applications. Here we report tunable coherent phonon dynamics with an architecture comprising three graphene mechanical resonators coupled in series, where all resonators can be manipulated by electrical signals on control gates. We demonstrate coherent Rabi oscillations between spatially separated resonators indirectly coupled via an intermediate resonator serving as a phonon cavity. The Rabi frequency fits well with the microwave burst power on the control gate. We also observe Ramsey interference, where the oscillation frequency corresponds to the indirect coupling strength between these resonators. Such coherent processes indicate that information encoded in vibrational modes can be transferred and stored between spatially separated resonators, which can open the venue of on-demand phonon-based information processing.

Residual behavior and risk assessment of butralin in peanut fields.

Butralin is widely used to control single-leaf weeds and some dicotyledons. The application of butralin in the environment may cause residue beyond regulation criteria and residual toxicity. Therefore, it is important to detect and supervise the dissipation behavior of butralin in edible raw food and in the environment. The aim of this study was to monitor butralin in peanuts and soil under farmland conditions and examine the likely dietary risk assessment of butralin for Chinese people on the basis of residual concentrations. A method for the analysis of butralin residue and its dissipation in peanut plants and soil under field conditions was investigated. The results show that an analytical method for the quantization of butralin in peanuts and soil utilizing gas chromatography with electron capture detection (GC-ECD) was developed. Standard recovery experiments using three different butralin spiking levels of 0.01, 0.1, and 1.0 mg kg-1 in different samples (i.e., peanut kernels, shell, seedling, stalk, and soil) were conducted. The recoveries of butralin from all matrices ranged from 86 to 108% with relative standard deviations from 3 to 6% (n = 5). The limit of quantification (LOQ) of the method was 0.01 mg kg-1. After storage at - 20 °C for 365 days, the degradation rate of residues of butralin in peanut kernels was less than 30%, which met the storage stability test criteria for pesticide residues in stored commodities of plant origin. The dissipation half-lives of butralin ranged from 4.2 to 6.6 days and 4.6 to 6.6 days in peanut seedlings and soil, respectively, in farmland ecosystems. At the normal harvest time, the final residue concentrations of butralin in peanuts and soil were all below the LOQ. The final total risk quotient (RQ) values were much lower than RQ = 100%, which indicated that the long-run fitness risk associated with butralin residue in different groups of registered crops is correspondingly low for people in China. The current research results could offer guidance for the rational use of butralin and provide data support for the building of maximum residue limits (MRLs) in China.

Ion Distribution Profiling in an Ion Mobility Spectrometer by Laser-Induced Fluorescence.

Measuring the ion distribution pattern in a drift tube under atmospheric pressure is very useful for studies of ion motion and design of ion mobility spectrometers (IMS); however, no mature method is available for conducting such measurements at present. We propose a simple and low-cost technique for profiling the two-dimensional ion distribution in any cross section of a drift tube. Similar to particle-image velocimetry, we first send sample ions with fluorescence properties into the drift tube and use a receiving plate to collect and accumulate them. Then, the receiving plate is illuminated by exciting light, and the ion distribution appears as a fluorescence image. In this study, Rhodamine 6G was selected as a typical fluorescence-tracer particle. Electrospray ionization (ESI) was chosen as an ionization source to keep the fluorophore undamaged. A plasma-cleaned coverslip was placed at the detection position as a receiving plate. When a layer of ions was collected, the slide was placed under the exciting light with a wavelength of 473 nm. A camera with a 490 nm high-pass light filter was used to capture the fluorescence image representing the ion distribution. The measured-ion detection efficiency of the method was 156 ion/dN, which is equivalent to the level of IonCCD. In addition, we studied the ion-passing characteristics of a Bradbury-Nielsen (BN) ion shutter and the ion-focusing effect in the drift tube using this method. The two-dimensional ion-distribution images behind the ion shutter and the images of the focused ion spot were first observed experimentally. Further theoretical analysis yielded the same conclusions as the experimental results, proving the feasibility of this method and producing a deeper understanding of ion motion in the IMS. This method has promising prospective application to the design, debugging, and optimization of IMS instruments and hyphenated systems.

Electrotunable artificial molecules based on van der Waals heterostructures.

Quantum confinement has made it possible to detect and manipulate single-electron charge and spin states. The recent focus on two-dimensional (2D) materials has attracted significant interests on possible applications to quantum devices, including detecting and manipulating either single-electron charging behavior or spin and valley degrees of freedom. However, the most popular model systems, consisting of tunable double-quantum-dot molecules, are still extremely difficult to realize in these materials. We show that an artificial molecule can be reversibly formed in atomically thin MoS2 sandwiched in hexagonal boron nitride, with each artificial atom controlled separately by electrostatic gating. The extracted values for coupling energies at different regimes indicate a single-electron transport behavior, with the coupling strength between the quantum dots tuned monotonically. Moreover, in the low-density regime, we observe a decrease of the conductance with magnetic field, suggesting the observation of Coulomb blockade weak anti-localization. Our experiments demonstrate for the first time the realization of an artificial quantum-dot molecule in a gated MoS2 van der Waals heterostructure, which could be used to investigate spin-valley physics. The compatibility with large-scale production, gate controllability, electron-hole bipolarity, and new quantum degrees of freedom in the family of 2D materials opens new possibilities for quantum electronics and its applications.

Tunable Hybrid Qubit in a GaAs Double Quantum Dot.

We experimentally demonstrate a tunable hybrid qubit in a five-electron GaAs double quantum dot. The qubit is encoded in the (1,4) charge regime of the double dot and can be manipulated completely electrically. More importantly, dot anharmonicity leads to quasiparallel energy levels and a new anticrossing, which help preserve quantum coherence of the qubit and yield a useful working point. We have performed Larmor precession and Ramsey fringe experiments near the new working point and find that the qubit decoherence time is significantly improved over a charge qubit. This work shows a new way to encode a semiconductor qubit that is controllable and coherent.

Temperature dependence of Coulomb oscillations in a few-layer two-dimensional WS2 quantum dot.

Standard semiconductor fabrication techniques are used to fabricate a quantum dot (QD) made of WS2, where Coulomb oscillations were found. The full-width-at-half-maximum of the Coulomb peaks increases linearly with temperature while the height of the peaks remains almost independent of temperature, which is consistent with standard semiconductor QD theory. Unlike graphene etched QDs, where Coulomb peaks belonging to the same QD can have different temperature dependences, these results indicate the absence of the disordered confining potential. This difference in the potential-forming mechanism between graphene etched QDs and WS2 QDs may be the reason for the larger potential fluctuation found in graphene QDs.

A gate defined quantum dot on the two-dimensional transition metal dichalcogenide semiconductor WSe2.

Two-dimensional layered materials, such as transition metal dichalcogenides (TMDCs), are promising materials for future electronics owing to their unique electronic properties. With the presence of a band gap, atomically thin gate defined quantum dots (QDs) can be achieved on TMDCs. Herein, standard semiconductor fabrication techniques are used to demonstrate quantum confined structures on WSe2 with tunnel barriers defined by electric fields, therefore eliminating the edge states induced by etching steps, which commonly appear in gapless graphene QDs. Over 40 consecutive Coulomb diamonds with a charging energy of approximately 2 meV were observed, showing the formation of a QD, which is consistent with the simulations. The size of the QD could be tuned over a factor of 2 by changing the voltages applied to the top gates. These results shed light on a way to obtain smaller quantum dots on TMDCs with the same top gate geometry compared to traditional GaAs/AlGaAs heterostructures with further research.

Suspending effect on low-frequency charge noise in graphene quantum dot.

Charge noise is critical in the performance of gate-controlled quantum dots (QDs). Such information is not yet available for QDs made out of the new material graphene, where both substrate and edge states are known to have important effects. Here we show the 1/f noise for a microscopic graphene QD is substantially larger than that for a macroscopic graphene field-effect transistor (FET), increasing linearly with temperature. To understand its origin, we suspended the graphene QD above the substrate. In contrast to large area graphene FETs, we find that a suspended graphene QD has an almost-identical noise level as an unsuspended one. Tracking noise levels around the Coulomb blockade peak as a function of gate voltage yields potential fluctuations of order 1 µeV, almost one order larger than in GaAs/GaAlAs QDs. Edge states and surface impurities rather than substrate-induced disorders, appear to dominate the 1/f noise, thus affecting the coherency of graphene nano-devices.