Search

The aim of our study was to illustrate the role of circular RNA 0120175 (circ_0120175) and its associated mechanism in laryngeal squamous cell carcinoma (LSCC) development. The abundance of circ_0120175, microRNA-330-3p (miR-330-3p) and solute carrier family 7, membrane 11 (SLC7A11) messenger RNA and protein was measured by quantitative real time polymerase chain reaction and Western blot assay. Cell proliferation, apoptosis, migration and invasion were assessed by cell counting kit-8 assay, flow cytometry and transwell migration and invasion assays, respectively. The interaction between miR-330-3p and circ_0120175 or SLC7A11 was confirmed by dual-luciferase reporter assay. Murine xenograft model was established to test the function of circ_0120175 in tumor growth in vivo. Circ_0120175 abundance was aberrantly increased in LSCC tissues and cell lines, and LSCC patients with high level of circ_0120175 were associated with advanced tumor staging, lymph node metastasis and short survival time. Circ_0120175 interference suppressed cell proliferation, migration and invasion and induced cell apoptosis of LSCC cells. Circ_0120175 could sponge and negatively regulate miR-330-3p expression in LSCC cells. The addition of anti-miR-330-3p partly reversed circ_0120175 knockdown-induced effects in LSCC cells. SLC7A11 bound to miR-330-3p. Circ_0120175 enhanced the abundance of SLC7A11 through sponging miR-330-3p in LSCC cells. Circ_0120175 silencing-mediated influences in LSCC cells were partly counteracted by the overexpression of SLC7A11. Circ_0120175 interference notably suppressed xenograft tumor growth in vivo. Circ_0120175 promoted proliferation, migration and invasion while impeded cell apoptosis of LSCC cells through miR-330-3p/SLC7A11 axis, which provided novel therapeutic targets for LSCC.

The optical properties of deep-ultraviolet (DUV) light-emitting diode (LED) with Al nanograting structure are investigated by three-dimensional (3D) finite-difference time-domain (FDTD) simulation. The peak intensity of TE and TM polarization radiation recombination rate of the grating structure is increased by 33.3% and 22.0% as compared to the control structure with Al plane. The light extraction efficiency (LEE) of the emitted light whose propagation direction is in the plane perpendicular to the Al-grating ridge is much higher than that in the plane parallel to the Al-grating ridge due to the scattering of the grating. Without considering the lateral surface extraction and packaging, the total LEE of the grating structure can be improved by 41.4% as compared to the control structure. The peak intensity of the output spectrum of the DUV LED with the grating structure can be increased by 70.3%.

Preservation fluid (PF) contamination, especially by multidrug-resistant (MDR) Gram-negative bacteria (GNB), poses a high risk of donor-derived infection (DDI) and severe clinical outcomes. We sought to determine whether the use of colistin sulfate to decontaminate PF in kidney transplantation can decrease the incidence of probable DDI (p-DDI) caused by MDR GNB.In a retrospective study of 916 recipients who received deceased donation, 864 PF samples were collected and cultured, and microbiological contaminants were recorded with the recipients' clinical data and outcomes. From March 2016 to May 2019, 624 samples were decontaminated with ceftizoxime, and from June 2019 to March 2021, 240 samples were decontaminated with colistin sulfate. Between-group comparisons were performed to assess the ability of the two decontamination regimens to decrease the incidence of p-DDI, especially MDR GNB-related infection.The overall PF contamination rate was 54.51% (471/864), and 80 samples were positive for MDR GNB contamination. All p-DDIs occurred in the ceftizoxime group (p 0.001), and 67.65% of p-DDIs were MDR GNB-related. In the ceftizoxime group, 23 of 61 cases of MDR GNB contamination led to related p-DDIs, while none occurred in the colistin sulfate group (p = 0.002). Among the 23 patients with p-DDIs, 5 died due to severe infection, and 2 experienced graft loss.The goal of decontamination should be to decrease the risk of MDR GNB-related p-DDI, and colistin sulfate could be an effective and feasible option.

Well-preserved and abundant planktonic foraminifera have been recovered from limestones of the Cretaceous oceanic red beds (CORBs) from the Yongla section in Gyangze, southern Tibet. This foraminiferal assemblage is dominated by species of Contusotruncana, Globotruncana, and Globotruncanita. The assemblage contains 21 species belonging to 7 genera and suggests a late Campanian to early Maastrichtian age, which permits amore precise age constraint for CORBs in the Gyangze area. This planktonic assemblage provides an important biostratigraphic datum for the correlations of theCORBs in theHimalayan region of the northern Tethys. The interval yielding foraminifers in the Yongla section may be the youngest known CORB in the Gyangze area.

Background: Preservation fluid (PF) contamination, especially contamination with multi-drug resistant (MDR) Gram-negative pathogens, poses a high risk of donor-derived infections (DDIs) and severe clinical outcomes. We sought to determine whether the use of colistin sulfate to decontaminate PF in kidney transplantation can decrease probable DDIs (p-DDIs) caused by MDR Gram-negative pathogens.Methods: In a retrospective study of 916 recipients who received deceased donation, 864 PF samples were collected and cultured, and microbiological contaminants were recorded with the recipients’ clinical data and outcomes. From March 2016 to May 2019, 624 samples were decontaminated with ceftizoxime; from June 2019 to March 2021, colistin sulfate was administered for PF decontamination in 240 samples. Between-group comparisons were performed to assess the ability of the two decontamination regimens to decrease p-DDIs, especially MDR Gram-negative pathogen-related infections.Results: The overall PF contamination rate was 53.36% (461/864), and 80 samples had MDR Gram-negative pathogen contamination. All p-DDIs occurred in the ceftizoxime group (pConclusions: The goal of decontamination should be decreasing MDR Gram-negative pathogen-related p-DDIs, and colistin sulfate could be an effective and feasible option.

Apoptosis of tubular epithelium cells (TECs) plays critical roles in renal ischemia reperfusion (I/R) injury, but the molecular regulatory mechanisms of apoptosis still require further investigation. Recently, phosphatase family members have been suggested to regulate multiple aspects of the injury and regeneration response. However, the roles of SHP-1, an important protein-tyrosine phosphatase, in the regulation of renal I/R injury remain unknown. Here, we found that SHP-1 knockdown in vivo significantly increased renal I/R injury and aggravated the apoptosis of TECs. Consistently, after SHP-1 knockdown in TECs in vitro, a sharp increase of apoptosis induced by cobalt dichloride was found. The protective role of SHP-1 was also validated in a TEC cell line stably overexpressing SHP-1. Mechanistically, the ASK1/MKK4/JNK pro-apoptosis signal was over activated after SHP-1 knockdown, and SHP-1 could bind to and dephosphorylate ASK1 to inhibit its activation, thus repressing apoptosis.

The effects of the modulation in the NH3 flow duty-ratio in a three-way pulsed-flow epitaxial growth process on the structural and optical properties of non-polar a-plane Al0.34Ga0.66N epi-layers were studied intensively. It was revealed that the typical pyramidal defects originated from the anisotropy in growth rate could be evidently reduced with an optimized NH3 flow duty-ratio. In fact, the root-mean-square value determined with atomic force microscope was decreased from 12.8 to 3.1 nm when the NH3 flow duty-ratio was increased from 0 to 0.57. Moreover, the LO-phonon-assisted exciton emission observed in the photoluminescence (PL) spectrum was remarkably suppressed, and the linewidth of the near band edge PL emission peak was decreased by 47%, implying the significantly enhanced optical properties of the non-polar a-plane Al0.34Ga0.66N epi-layer.

The optical polarization characteristics of surface plasmon (SP) coupled AlGaN-based light emitting diodes (LEDs) are investigated theoretically by analyzing the radiation recombination process and scattering process respectively. For the Al0.5Ga0.5N/Al/Al2O3 slab structure, the relative intensity of TE-polarized and TM-polarized spontaneous emission (SE) rate into the SP mode obviously depends on the thickness of the Al layer. The calculation results show that TM dominated emission will be transformed into TE dominated emission with the decrease of the Al thickness, while the emission intensities of both TE/TM polarizations will decrease significantly. In addition, compared with TM polarized emission, TE polarized emission is easier to be extracted by SP coupling. For the Al0.5Ga0.5N/Al nano-particle structure, the ratio of transmittance for TE/TM polarized emission can reach ∼ 3.06, while for the Al free structure, it is only 1.2. Thus, the degree of polarization of SP coupled LED can be improved by the reasonable structural design.

Background Patients with early-stage renal cell carcinoma (RCC) are considered to be eligible donors. Although preliminary experience in using kidneys of specific pathologic types, mainly those with small renal masses (SRMs), have been established, multiorgan utilization of the same donor with SRMs is limited. Methods One deceased donor whose left-side kidney was diagnosed with Fuhrman grade I RCC was included. The tumor mass in the kidney was removed through partial nephrectomy according to the gold standard. Then, 3 transplant surgeries were performed, in which 1 recipient accepted kidney transplant after tumor exeresis, 1 simultaneous heart-kidney (the contralateral one) transplant, and 1 liver transplant. Recipients were followed up according to our standard protocol for renal cancers. (All allografts were allocated in compliance with the Declaration of Helsinki and the Declaration of Istanbul.) Results After 32 months, no radiographic findings showed any morphologic changes of the lesion, and all patients were in good condition, with neither tumor recurrence nor allograft rejection or infection. No complaints such as pain, oliguria, dyspnea, nausea, or fatigue were recorded. Conclusions To the best of knowledge, this initial work takes the lead in elaborating the organ utilization of multiorgan donors with SRMs. We hope the experience will provide support for cross discussion concerned with multiorgan transplant from tumor-affected donors in clinical practices, further expand the donor pool and address the donor shortage problem.

To further improve the performance of all-inkjet-printing ZnO UV photodetector and maintain the advantages of inkjet printing technology, the inkjet printing Ag nanoparticles (NPs) were deposited on the inkjet printing ZnO UV photodetector for the first time. The inkjet printing Ag NPs can passivate the surface defects of ZnO and work as surface plasmons from the characterization of photoluminescence (PL), X-ray photoelectron spectroscopy (XPS), and finite difference time domain method (FDTD) simulation. The normalized detectivity (D*) of the Ag NP-modified detector reaches to 1.45 × 1010 Jones at 0.715 mW incident light power, which is higher than that of 5.72 × 109 Jones of the bare ZnO photodetector. The power-law relationship between the photocurrent and the incident light power of the Ag NP-modified ZnO detector is Ipc ∝ P2.34, which means the photocurrent is highly sensitive to the change of incident light power.

The International Pediatric Nephrology Association (IPNA) Global Kidney Replacement Therapy (KRT) Registry was established to evaluate the incidence and outcomes of kidney replacement therapy (dialysis and transplantation) provided to children worldwide. Analysis of registry data for separate regions is feasible.Three centers located in Shanghai, Guangzhou, and Zhengzhou, which have the greatest number of pediatric kidney transplantation cases in China, participated in this analysis of transplant data. Data were registered by each center for patients under the age of 19 years who received a single-organ kidney transplant for the first time between 2011 and 2018.In total, 415 patients (59.8% male) aged 1.4-18.7 (median 12.1) years were followed for 0.3-97.1 (median 27.7) months. The number of kidney transplants increased from a total of 129 during 2011-2014 to 286 cases during 2015-2018. 85.8% of patients received the transplanted kidney from a pediatric (age 19 years) donor, and deceased donors accounted for 94% of all donors. 8.0% of grafts were lost. One and 5-year patient survival rates were 97.6% and 95.5%, respectively. The major cause of death was infection (7/14). Similar graft and patient survival rates were observed for organs from pediatric and adult donors in 6-11 and 12-18 year recipient age groups, whereas recipients 6 years showed inferior patient and graft survival.Pediatric kidney transplantation shows favorable short-term and medium-term outcomes in China. Our experience supports use of pediatric donors in pediatric kidney transplantation, but attention directed to the outcome of recipients aged under 6 is necessary. Graphical abstract.

Biogenic reefs are one of two major depositional types in the South China Sea, and are constructed by coral, algae and bryozoa. The West Pacific is a major area of biogenic reef development and plays a critical role in the global carbon cycle. However, the lack of geochronological studies in previous works inhibits our understanding of their contributions. Herein, we conduct a cyclostratigraphic and magnetostratigraphic study on Neogene biogenic reefs using the XK-1 core that was drilled at the Shidao Island, Xisha (Paracel) Islands. The main findings of this study are: (1) the establishment of reliable magentostratigraphy for Ledong, Huangliu, Meishan and Sanya Formations; (2) the magnetic susceptibility variation can be inferred as growth index and tuned to the 405-ka long eccentricity cycle; (3) the astronomical geochronology suggests that the bottom ages for Ledong, Yinggehai, Huangliu, Meishan, and Sanya Formations are 2.2 Ma, 5.7 Ma, 10.4 Ma, 16.6 Ma, and 24.3 Ma, respectively; and (4) Earths eccentricity and obliquity played predominant roles in biogenic reef establishment on orbital to tectonic timescales. Thus, the reported geochronology offers an opportunity to test the contributions of various factors and hypothesize their roles in the global carbon cycle in future.

We studied 344 samples from Well XK-1 in Xisha Islands, South China Sea, and identified 66 species of larger benthic foraminifera, providing critical evidence for biostratigraphy and palaeoenvironmental interpretation of the Miocene reef carbonate sequence. Three assemblages are recognized, namely, Spiroclypeus higginsi – Borelis pygmaeus Assemblage (Letter Stage Te5, Early Miocene, 1256.28–1180.15 m), Nephrolepidina – Miogypsina Assemblage (Tf, Middle Miocene, 1031.10–577.04 m), and Cycloclypeus – Heterostegina Assemblage (Tg, Late Miocene, 468.13–380.42 m). On the basis of the palaeoecological preference of the larger foraminifera, we interpret that the Miocene carbonate sequence was deposited mainly in a warm tropical shallow water environment, characterized by five stages of continuous long-term evolution: backreef lagoon to shelf in the Early Miocene, normal to frontal reef in the early Middle Miocene, backreef lagoon to shelf in the later Middle Miocene, normal to frontal reef in the early Late Miocene, and proximal forereef shelf in the later Late Miocene.

Renal ischemia-reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI) and may influence renal graft survival. In this study, we investigate the involvement of SIRT3 and DRP1 in mitochondrial autophagy and AKI in a mouse model of IRI. Autophagy was detected in the absence of SIRT3, and hypoxic reoxygenation (H/R) experiments using renal tubular epithelial cells NRK52E were performed in vitro to validate these results. We found that autophagosomes increased following IRI and that the expression of autophagy-related genes was up-regulated. The inhibition of autophagy with 3-methyladenine exacerbated IRI, whereas the DRP1 inhibitor Mdivi-1 reversed this inhibition. Mdivi-1 did not reverse the inhibition of autophagy in the absence of SIRT3. During IRI, Mdivi-1 reduced autophagy and DRP1 expression, whereas SIRT3 overexpression attenuated this condition. Rescue experiment showed that autophagy was increased when both SIRT3 or DRP1 were over- or under-expressed or just DRP1 was under-expressed but expression was reduced when just SIRT3 was under-expressed. However, the expression of DRP1-related molecules was reduced when SIRT3 was overexpressed and when DRP1 was under-expressed. Taken together, these findings indicate that SIRT3 protects against kidney damage from IRI by modulating the DRP1 pathway to induce mitochondrial autophagy.

This research demonstrates a p-GaN gate AlGaN/GaN high electron mobility transistor with beta-Ga2O3 back barrier and investigates the electric characteristics of the device. The simulated results show that the threshold voltage of the device will increase with the use of the Ga2O3 back barrier. Moreover, the off-state leakage current level is one order of magnitude lower than the device without back barrier, which can be attributed to the rise of the conduction band diagram in the buffer layer and the decrease of the electron current density released by ionized accept traps. In addition, the impacts of the beta-Ga2O3 back barrier thickness are investigated, and the results show that with increasing Ga2O3 thicknesses, the threshold voltage of the device decreases while the leakage current of the device increases.

To improve the performance of the conventional p-GaN gate AlGaN/GaN high electron mobility transistors (HEMTs), we propose an improved design for e-mode AlGaN/GaN HEMT with a gate stack β-Ga2O3/p-GaN structure. The simulated results show that the proposed device increases the threshold voltage and the gate breakdown voltage in comparison with the conventional p-GaN gate HEMT due to the use of the β-Ga2O3 layer, which has an additional β-Ga2O3/p-GaN heterojunction and decreases the strength of electric field in the gate region. Moreover, the proposed device exhibits a lower off-state leakage current, which can be attributed to the less donor ionized density. In addition, the impacts of the β-Ga2O3 layer thickness are investigated. There is a trade-off between β-Ga2O3 layer thickness and the performance of the proposed device, including threshold voltage, gate breakdown, and saturation drain current.

This research investigates electrical properties of E-mode AlGaN/GaN HEMTs with n-type β-Ga2O3/p-GaN gate stack under different gate work functions of 4.6, 5.1 and 5.7 eV, respectively. The simulated results show that the device with gate work function of 5.7 eV exhibits the largest threshold voltage of 2.8 V while having the lowest saturation drain current of 0.15 A mm−1, which can be ascribed to the device having the highest Schottky barrier, leading to the least electrons collected at the AlGaN/GaN interface. Moreover, the device with gate work function of 5.7 eV shows the largest gate breakdown voltage as well as the lowest off-state gate leakage, which can be attributed to the least strength of electric field in the Ga2O3 layer. Additionally, the Fowler–Nordheim equation was used to study the mechanisms of off-state leakage.

GaN-based light emitting diodes (LEDs) have been grown by metalorganic chemical vapor deposition on Si(111) substrate with and without 3C-SiC intermediate layer (IL). Structural property has been characterized by means of atomic force microscope, X-ray diffraction, and transmission electron microscope measurements. It has been revealed that a significant improvement in crystalline quality of GaN and superlattice epitaxial layers can be achieved by using 3C-SiC as IL. Regarding of electrical and optical characteristics, it is clearly observed that the LEDs with its IL have a smaller leakage current and higher light output power comparing with the LEDs without IL. The better performance of LEDs using 3C-SiC IL can be contributed to both of the improvements in epitaxial layers quality and light extraction efficiency. As a consequence, in terms of optical property, a double enhancement of the light output power and external quantum efficiency has been realized.

For the [0001] oriented AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs), the holes in the p-type electron blocking layer (p-EBL) are depleted due to the polarization induced positive sheet charges at the last quantum barrier (LQB)/p-EBL interface. The hole depletion effect significantly reduces the hole injection capability across the p-EBL. In this work, we propose inserting a thin AlN layer between the LQB and the p-EBL, which can generate the hole accumulation at the AlN/p-EBL interface. Meanwhile, the holes can obtain the energy when traveling from the p-EBL into the multiple quantum wells (MQWs) by intraband tunneling through the thin AlN layer. As a result, the hole injection and the external quantum efficiency (EQE) have been remarkably enhanced. Moreover, we point out that the thick AlN insertion layer can further generate the hole accumulation in the p-EBL and increase the hole energy which helps to increase the hole injection. We also prove that the intraband tunneling for holes across the thick AlN insertion layer is facilitated by using the optimized structure.

Acute kidney injury (AKI), which involves the loss of kidney function caused by damage to renal tubular cells, is an important public health concern. We previously showed that sirtuin (SIRT)3 protects the kidneys against mitochondrial damage by inhibiting the nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3) inflammasome, attenuating oxidative stress, and downregulating proinflammatory cytokines. In this article, we investigated the role of autophagy, mediated by a mammalian target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK), in the protective effect of SIRT3, against sepsis-induced AKI, in a mouse model of cecal ligation and puncture (CLP). The AKI in CLP mice was associated with the upregulation of autophagy markers; this effect was abolished in SIRT3- mice in parallel with the downregulation of phospho (p)-AMPK and the upregulation of p-mTOR. Pretreatment with the autophagy inhibitor 3-methyladenine (3-MA) or AMPK inhibitor compound isotonic saline (C), exacerbated AKI. SIRT3 overexpression promoted autophagy, upregulated p-AMPK and downregulated p-mTOR in CLP mice, attenuating sepsis-induced AKI, tubular cell apoptosis, and inflammatory cytokine accumulation in the kidneys. The blockage of autophagy induction largely abolished the protective effect of SIRT3 in sepsis-induced AKI. These findings indicate that SIRT3 protects against CLP-induced AKI by inducing autophagy through regulation of the AMPK/mTOR pathway.

The influence of quantum-well (QW) width on electroluminescence properties of AlGaN deep ultraviolet light-emitting diodes (DUV LEDs) was studied at different temperatures. The maximum external quantum efficiency (EQE) ratios of LED with 3.5 nm QW to that with 2 nm increased from 6.8 at room temperature (RT) to 8.2 at 5 K. However, the ratios for LED with 3.5 nm QW to that with 5 nm QW decreased from 4.8 at RT to 1.6 at 5 K. The different changes of EQE ratios were attributed to the decrease of non-radiative recombination and the increase of volume of the active region. From theoretical analysis, the LED with 2-nm wells had a shallowest barrier for electron overflow due to the quantum-confined effect, whereas the LED with 5-nm wells showed the least overlap of electron and hole due to the large internal field. Therefore, the LED with 3.5 nm QW had the highest maximum EQE at the same temperature. As temperature decreased, the current for maximum EQE decreased for all the LEDs, which was believed to be due to the increase of electron which overflowed out of QWs and the decrease of hole concentration. The results were helpful for understanding the combination of polarization effect and electron overflow in DUV LEDs.

The optical properties of AlGaN-based quantum well (QW) structure with two coupled thin well layers are investigated by the six-by-six K – P method. Compared with the conventional structure, the new structure, especially the one with lower Al-content in the barrier layer, can enhance the TE-/TM-polarized total spontaneous emission rate due to the strong quantum confinement and wide recombination region. For the conventional QW structure, the reduction of well thickness can lead the degree of polarization (DOP) to decrease and the internal quantum efficiency (IQE) to increase. By using the coupled thin well layers, the DOP for the structure with high Al-content in the barrier layer can be improved, while the DOP will further decrease with low Al-content in the barrier layer. It can be attributed to the band adjustment induced by the combination of barrier height and well layer coupling. The IQE can also be further enhanced to 14.8%–20.5% for various Al-content of barrier layer at J = 100 A/cm2. In addition, the efficiency droop effect can be expected to be suppressed compared with the conventional structure.

A blue light emitting diode (LED) chip has been facilely fabricated on a 4-inch patterned sapphire substrate based on an InGaN/GaN multiple quantum well structure, composed of a Ce3+ doped Yttrium Aluminum Garnet (YAG) yellow phosphor packaged into a white LED chip. The epitaxial growth, fabrication, and package process of the device have been briefly described; the structural properties and device performance have also been systematically studied. The surface morphology of the sample in a whole wafer has a good uniformity. And the curvature distribution with a maximum value of ~70 μm, it gradually becomes smaller from the middle to the periphery, which is mainly resulting from the strain state evolution during the film growth. When increasing the injection current, it is significant interestingly observed in the electroluminescence (EL) spectrum that the blue light peak is blue-shifted, it is due to the influence reducing of the polarization field and/or the energy band filling, while the blue light peak and the yellow-green light peak are red-shifted due to the thermal effect of the chip. In addition, the light output power exhibits a linearly incremental relationship with a little saturation when the injection current varies from 0 to 100 mA. Therefore, it is firmly believed that the corresponding chip fabrication and characterization technology will play a certain role in promoting the development of solid-state lighting field.

Interleukin-22 (IL-22) is an inflammatory cytokine mainly produced by activated Th17 and Th22 cells. The data presented here demonstrate that IL-22 induced the migration and invasion of papillary thyroid cancer (PTC) cells. MicroRNA expression analysis and functional studies indicated that IL-22-mediated migration and invasion is positively regulated by miR-595. Further mechanistic studies revealed that sex-determining region Y-box 17 (Sox17) is directly targeted by miR-595. We then demonstrated that IL-22 regulated migration and invasion of PTC cells via inhibiting Sox17 expression. Interestingly, in PTC cell lines and PTC tissues, expression of IL-22 and miR-595 was upregulated and Sox17 downregulated compared with normal thyroid, and their expression levels were closely correlated. Taken together, this present study suggests that IL-22 stimulation enhances the migration and invasion of PTC cells by regulating miR-595 and its target Sox17.

A series of AlN/GaN heterostructures were grown on 150 mm Si substrates by metal organic chemical vapor deposition (MOCVD). Different cap layer structures, including gallium nitride (GaN) and silicon nitride (SiNx), were used to passivate the heterostructure surface. A 3.5 nm thick SiNx cap is able to maintain the two dimensional electron gas (2DEG) stability in a long period. An AlN/GaN heterostructure with a 4.5 nm thick AlN barrier exhibits the best 2DEG properties, in terms of sheet resistance, carrier mobility and stability. The carrier mobility of the 2DEG can be enhanced by a combination of SiNx and GaN cap layers to over 1400 cm2/Vs.

Aquatic algae are the main biotic source of organics in both marine and terrestrial hydrocarbon source rocks. Unlike marine deposits, fossil evidence of algal remains in terrestrial source rocks is rare, especially in pre-Cenozoic rocks. However, abundant algae-related biomarkers are commonly found in terrestrial oil-bearing basins. We conducted a palynological study of the source rocks in the Lower Cretaceous Xiagou Formation in the Jiuquan Basin, northwestern China. The abundant planktonic algae comprise dinoflagellate cysts (Zhongyuandinium decorosum, Parabohaidina (Conicoidium) tuberculata and Palaeoperidinium sp.) and chlorophyta (Botryococcus sp. and Tetrastrum multifilorum). These algae are extremely transparent, which makes their identification difficult. However, they show high yellow fluorescence under blue light which increases the clarity of surface ornamentation. In addition, the Lower Cretaceous Xiagou Formation is characterized by fine laminated deposits. The lamination consists of light- and dark-colored laminae couplets with thickness of approximately 0.03–0.5 mm. The dark laminae are rich in algae and amorphous organic matter (AOM). Algal remains are densely distributed along the bedding surface and show a strong yellow color under blue fluorescence. The algal remains probably played an important role in oil-generating microlayers in the source rock. In contrast, the organic components in the light-colored laminae are dominated by phytoclasts. Additionally, the biomarkers 4-methylsterane and dinosterane have also been detected in fossil-bearing beds, providing further evidence that dinoflagellate cysts flourished in the Jiuquan Basin during the Early Cretaceous. Thus, these aquatic algae are not only the likely source of oil in the Lower Cretaceous source rocks in the Jiuquan Basin but also suggest that blooms of early dinoflagellate cysts occurred in continental interiors during the Early Cretaceous.