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Electron spins in silicon quantum dots are a promising platform for fault-tolerant quantum computing. Low-frequency noise, including nuclear spin fluctuations and charge noise, is a primary factor limiting gate fidelities. Suppressing this noise is crucial for high-fidelity qubit operations. Here, we report on a two-qubit quantum device in natural silicon with universal qubit control, designed to investigate the upper limits of gate fidelities in a non-purified Si/SiGe quantum dot device. By employing advanced device structures, qubit manipulation techniques, and optimization methods, we have achieved single-qubit gate fidelities exceeding 99% and a two-qubit controlled-Z (CZ) gate fidelity of 91%. Decoupled CZ gates are used to prepare Bell states with an average fidelity of 91%, typically exceeding previously reported values in natural silicon devices. These results underscore that even natural silicon has the potential to achieve high-fidelity gate operations, particularly with further optimization methods to suppress low-frequency noise. [ABSTRACT FROM AUTHOR]

Adsorbed natural gas (ANG) systems involve using porous materials to increase the working capacity and/or reduce the storage pressure compared to compressed natural gas (CNG). Flexible metal‐organic materials (FMOMs) are particularly interesting in this context since their stepped isotherms can afford increased working capacity if the adsorption/desorption steps occur within the proper pressure range. We report herein that metal doping in a family of isostructural FMOMs, ML2 (M=Co, Ni or NixCo1−x, L=4‐(4‐pyridyl)‐biphenyl‐4‐carboxylic acid), enables control over the gate opening between non‐porous (closed) and porous (open) phases at pressures relevant to methane storage. Specifically, methane‐induced phase transformations can be fine‐tuned by using different Ni/Co ratios to enhance methane working capacity. The optimal working capacity from 5 to 35 bar at 298 K (153 cm3 cm−3) was found for Ni0.89Co0.11L2 (X‐dia‐1‐Ni0.89Co0.11), which is greater than that of benchmark rigid MOFs. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Carbon dioxide (CO2) capture is one of the most important aspects of reducing global warming. In terms of CO2 capture, metal‐organic frameworks (MOFs) have several advantages. However, it isn't easy to shape MOFs while maintaining their performance. Herein, we describe the development of a pellet‐shaped ultramicroporous MOF, Ni(3‐ain)2 (3‐ain = 3‐aminoinoisonicotinic acid), that is capable of selectively adsorbing CO2. Polyvinyl butyral (PVB) is used as a binder during the production of Ni(3‐ain)2 MOF pellets. The adequately shaped material can maintain its crystallinity and exhibit a high CO2 adsorption capacity (3.73 mmol·g–1) at ambient conditions, which is significantly greater than those obtained for N2 (0.63 mmol·g–1) and CO (0.90 mmol·g–1). Consequently, this material displays high IAST selectivities for CO2/N2 (26.3, 15/85, V/V) and CO2/CO (19.2, 1/99, V/V). According to the theoretical calculations, Ni(3‐ain)2 preferentially adsorbs CO2 molecules over N2 molecules and CO molecules. The results of experiments on dynamic breakthrough have demonstrated that Ni(3‐ain)2 pellets are capable of effectively separating CO2/N2 or CO2/CO mixtures under conditions of dynamic flow. Furthermore, the structured MOF materials can be synthesized in one step at kilogram scale. This work provides an avenue for the shaping of MOFs for potential industrial applications in the future. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Carbon dioxide (CO2) capture is one of the most important aspects of reducing global warming. In terms of CO2 capture, metal‐organic frameworks (MOFs) have several advantages. However, it isn't easy to shape MOFs while maintaining their performance. Herein, we describe the development of a pellet‐shaped ultramicroporous MOF, Ni(3‐ain)2 (3‐ain = 3‐aminoinoisonicotinic acid), that is capable of selectively adsorbing CO2. Polyvinyl butyral (PVB) is used as a binder during the production of Ni(3‐ain)2 MOF pellets. The adequately shaped material can maintain its crystallinity and exhibit a high CO2 adsorption capacity (3.73 mmol·g–1) at ambient conditions, which is significantly greater than those obtained for N2 (0.63 mmol·g–1) and CO (0.90 mmol·g–1). Consequently, this material displays high IAST selectivities for CO2/N2 (26.3, 15/85, V/V) and CO2/CO (19.2, 1/99, V/V). According to the theoretical calculations, Ni(3‐ain)2 preferentially adsorbs CO2 molecules over N2 molecules and CO molecules. The results of experiments on dynamic breakthrough have demonstrated that Ni(3‐ain)2 pellets are capable of effectively separating CO2/N2 or CO2/CO mixtures under conditions of dynamic flow. Furthermore, the structured MOF materials can be synthesized in one step at kilogram scale. This work provides an avenue for the shaping of MOFs for potential industrial applications in the future. [ABSTRACT FROM AUTHOR]

In the electronics industry, the efficient recovery and capture of sulfur hexafluoride (SF6) from SF6/N2 mixtures is of great importance. Herein, three metal–organic frameworks with fine‐tuning pore structures, Cu(peba)2, Ni(pba)2, and Ni(ina)2, were designed for SF6 capture. Among them, Ni(ina)2 has perfect pore sizes (6 Å) that are comparable to the kinetic diameter of sulfur hexafluoride (5.2 Å), affording the benchmark binding affinity for SF6 gas. Ni(ina)2 exhibits the highest SF6/N2 selectivity (375.1 at 298 K and 1 bar) and ultra‐high SF6 uptake capacity (53.5 cm3 g−1 at 298 K and 0.1 bar) at ambient conditions. The remarkable separation performance of Ni(ina)2 was verified by dynamic breakthrough experiments. Theoretical calculations and the SF6‐loaded single‐crystal structure provided critical insight into the adsorption/separation mechanism. This porous coordination network has the potential to be used in industrial applications. [ABSTRACT FROM AUTHOR]

The enrichment and purification of coal‐bed methane provides a source of energy and helps offset global warming. In this work, we demonstrate a strategy involving the regulation of the pore size and pore chemistry to promote the separation of CH4/N2 mixtures in four nickel‐based coordination networks, named Ni(ina)2, Ni(3‐ain)2, Ni(2‐ain)2, and Ni(pba)2, (where ina=isonicotinic acid, 3‐ain=3‐aminoisonicotinic acid, 2‐ain=2‐aminoisonicotinic acid, and pba=4‐(4‐pyridyl)benzoic acid). Among them, Ni(ina)2 and Ni(3‐ain)2 can effectively separate CH4 from N2 with top‐performing performance because of the suitable pore size (≈0.6 and 0.5 nm) and pore environment. Explicitly, Ni(ina)2 exhibits the highest ever reported CH4/N2 selectivity of 15.8 and excellent CH4 uptake (40.8 cm3 g−1) at ambient conditions, thus setting new benchmarks for all reported MOFs and traditional adsorbents. The exceptional CH4/N2 separation performance of Ni(ina)2 is confirmed by dynamic breakthrough experiments. Under different CH4/N2 ratios, Ni(ina)2 selectively extracts methane from the gaseous blend and produces a high purity of CH4 (99 %). Theoretical calculations and CH4‐loading single‐crystal structure analysis provide critical insight into the adsorption/separation mechanism. Ni(ina)2 and Ni(3‐ain)2 can form rich intermolecular interactions with methane, indicating a strong adsorption affinity between pore walls and CH4 molecules. Importantly, Ni(ina)2 has good thermal and moisture stability and can easily be scaled up at a low cost ($25 per kilogram), which will be valuable for potential industrial applications. Overall, this work provides a powerful approach for the selective adsorption of CH4 from coal‐bed methane. [ABSTRACT FROM AUTHOR]

Insertion mutagenesis has become one of the most popular methods for gene functions analysis. Here we report a two-element Ac/Ds transposon system containing enhancer trap and gene trap for gene tagging in rice. The excision of Ds element was examined by PCR amplification. The excision frequency of Ds element varied from 0% to 40% among 20 F2 populations derived from 11 different Ds parents. Southern blot analysis revealed that more than 70% of excised Ds elements reinserted into rice genome and above 70% of the reinserted Ds elements were located at different positions of the chromosome in rice. The result of histochemical GUS analysis indicated that 28% of enhancer trap and 22% of gene trap tagging plants displayed GUS activity in leaves, roots, flowers or seeds. The GUS positive lines will be useful for identifying gene function in rice. [ABSTRACT FROM AUTHOR]

Scaling up quantum dots to two-dimensional (2D) arrays is a crucial step for advancing semiconductor quantum computation. However, maintaining excellent tunability of quantum dot parameters, including both nearest-neighbor and next-nearest-neighbor couplings, during 2D scaling is challenging, particularly for silicon quantum dots due to their relatively small size. Here, we present a highly controllable and interconnected 2D quantum dot array in planar silicon, demonstrating independent control over electron fillings and the tunnel couplings of nearest-neighbor dots. More importantly, we also demonstrate the wide tuning of tunnel couplings between next-nearest-neighbor dots, which play a crucial role in 2D quantum dot arrays. This excellent tunability enables us to alter the coupling configuration of the array as needed. These results open up the possibility of utilizing silicon quantum dot arrays as versatile platforms for quantum computing and quantum simulation.

Separating ethane (C 2 H 6 ) from ethylene (C 2 H 4 ) is an essential and energy-intensive process in the chemical industry. Here, we report two flexible diamondoid coordination networks, X-dia-1-Ni and X-dia-1-Ni 0.89 Co 0.11 , that exhibit gate-opening between narrow-pore (NP) and large-pore (LP) phases for C 2 H 6 , but not for C 2 H 4 . X-dia-1-Ni 0.89 Co 0.11 thereby exhibited a type F-IV isotherm at 273 K with no C 2 H 6 uptake and a high uptake (111 cm 3 g -1 , 1 atm) for the NP and LP phases, respectively. Conversely, the LP phase exhibited a low uptake of C 2 H 4 (12.2 cm 3 g -1 ). This C 2 H 6 /C 2 H 4 uptake ratio of 9.1 for X-dia-1-Ni 0.89 Co 0.11 far surpassed those of previously reported physisorbents, many of which are C 2 H 4 -selective. In situ variable-pressure X-ray diffraction and modeling studies provided insight into the abrupt C 2 H 6 -induced structural NP to LP transformation. The promise of pure gas isotherms and, more generally, flexible coordination networks for gas separations was validated by dynamic breakthrough studies, which afforded high-purity (99.9%) C 2 H 4 in one step.

The capture and separation of fluorinated gases (F-gases) from N 2 has the potential to not only reduce greenhouse gas emissions but also provide economic benefits for the semiconductor industry. In this work, two Ni-based metal-organic frameworks (MOFs), Ni-MOF (Ni(ina) 2 , ina = isonicotinic acid) and amine-functionalized NH 2 -Ni-MOF (Ni(3-ain) 2 , 3-ain = 3-aminoisonicotinic acid), were constructed for capturing F-gases (CF 4 and NF 3 ). At ambient conditions, both materials exhibit very high CF 4 sorption capacities (2.92 mmol g -1 for Ni-MOF and 2.69 mmol g -1 for NH 2 - Ni-MOF) . In addition, NH 2 -Ni-MOF exhibited a record selectivity of 46.3 for the CF 4 /N 2 mixture at 298 K and 100 kPa, surpassing all benchmark adsorbents, including Ni-MOF (34.7). The kinetic adsorption tests demonstrated that Ni-MOF and NH 2 -Ni-MOF performed well for CF 4 /N 2 and NF 3 /N 2 mixtures. According to grand canonical Monte Carlo (GCMC) simulations, CF 4 or NF 3 interacts with NH 2 -Ni-MOF by multiple van der Waals interactions, resulting in stronger interaction than N 2 . More importantly, dynamic breakthrough experiments verified the practical separation potential of the two materials for CF 4 /N 2 and NF 3 /N 2 mixtures.

Aims and Background: To ascertain the value of the detection of urinary modified nucleosides in the early diagnosis and prognostic monitoring of urothelial bladder cancer., Methods: One hundred seventeen patients with urothelial bladder carcinoma and 66 healthy volunteers were included in the study. High-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC/ESI-Q-TOF-MS) was used to measure the levels of urinary modified nucleosides in the bladder cancer and control groups. Postoperative monitoring was done every 3 months in patients with noninvasive carcinoma; 85 patients attended the 1-year follow-up visit., Results: The levels of m1A, ac4C, O6-MeG and 1-MeI were significantly higher in cases than controls (P < 0.05). The highest sensitivity (92.45%) and specificity (87.50%) were obtained when 1-MeI detection was combined with m1A detection. The m1A and 1-MeI levels 3 months after operation in both patient groups were significantly lower than the preoperative levels (P < 0.01). The no-recurrence group subsequently maintained low levels, but in the recurrence group the levels rose again almost to preoperative values. At 6, 9 and 12 months after operation, the m1A and 1-MeI levels of the recurrence group were higher than those of the no-recurrence group and the control group (P < 0.01)., Conclusions: Urinary modified nucleosides might become novel tumor markers that will facilitate the clinical management and will be helpful in the diagnosis and follow-up of urothelial bladder cancer. m1A and 1-MeI appear to be most promising for clinical use and be worthy of further study in the near future.

Background: Colonic neuroendocrine neoplasms (NENs) are relatively rare tumors with an incidence rate of 0.11-0.21/100,000. NENs account for approximately 0.4% of colorectal neoplasms. Cutaneous metastases of colonic neuroendocrine carcinomas (NECs) are very infrequent, while cases of scalp metastasis are even fewer. Cutaneous metastases are more rare than visceral metastases and usually develop later; therefore, cutaneous metastases as initial distant metastases can be easily overlooked. This is the second case report of a colonic NEC with scalp metastasis. Compared with the previous case, in this instance scalp metastasis developed before visceral metastasis, and the cutaneous lesions were confined to the scalp alone., Case Presentation: A 62-year-old Chinese man, who had undergone radical surgery for a "locoregional" colonic NEC one and half months before, came to our hospital for adjuvant chemotherapy. We found multiple scalp nodules during physical examination. Moreover, these nodules had occurred and had not been detected prior to the patient undergoing radical surgery. The scalp nodules proved to be metastases from colonic NEC as determined using pathological and immunohistochemical examinations following lumpectomy. After one and half months, visceral metastases were detected in this patient. Ultimately, the patient died two months later., Conclusions: In this report an unusual case of a colonic NEC with initial distant metastasis confined to the scalp is presented. This case is unusual because of the development of cutaneous metastasis before visceral metastasis. The scalp metastasis were initially overlooked, leading to inaccurate staging and radical surgery that was not curative. This demonstrates that distant metastasis can occur during the early phase of tumor growth in these aggressive lesions. Thus, the possibility of distant metastases should be assessed in the initial work up to avoid mistaken clinical staging especially when distant metastases occur only in skin.

Urinary-modified nucleosides have a potential role as cancer biomarkers for a number of malignant diseases. High performance liquid chromatography (HPLC) was combined with full-scan mass spectrometry, MS/MS analysis and accurate mass measurements in order to identify purine nucleosides purified from urine. Potential purine nucleosides were assessed by their evident UV absorbance in the HPLC chromatogram and then further examined by the mass spectrometric techniques. In this manner, numerous modified purine nucleosides were identified in the urine samples from cancer patients including xanthine, adenosine, N1-methyladenosine, 5'-deoxy-5'-methylthioadenosine, 2-methyladenosine, N6-threonylcarbamoyladenosine, inosine, N1-methylinosine, guanosine, N1-methylguanosine, N7-methylguanine, N2-methylguanosine, N2,N2-dimethyguanosine, N2,N2,N7-trimethylguanosine. Furthermore, a number of novel purine nucleosides were tentatively identified via critical interpretation of the combined mass spectrometric data including N3-methyladenosine, N7-methyladenine, 5'-dehydro-2'-deoxyinosine, N3-methylguanine, O6-methylguanosine, N1,N2,N7-trimethylguanosine, N1-methyl-N2-ethylguanosine and N7-methyl-N1-ethylguanosine., (2009 John Wiley & Sons, Ltd.)