Crystal Structure of a Human Single Domain Antibody Dimer Formed through VH-VH Non-Covalent Interactions

Single-domain antibodies (sdAbs) derived from human VH are considered to be less soluble and prone to aggregate which makes it difficult to determine the crystal structures. In this study, we isolated and characterized two anti-human epidermal growth factor receptor-2 (HER2) sdAbs, Gr3 and Gr6, from a synthetic human VH phage display library. Size exclusion chromatography and surface plasmon resonance analyses demonstrated that Gr3 is a monomer, but that Gr6 is a strict dimer. To understand this different molecular behavior, we solved the crystal structure of Gr6 to 1.6 Å resolution. The crystal structure revealed that the homodimer assembly of Gr6 closely mimics the VH-VL heterodimer of immunoglobulin variable domains and the dimerization interface is dominated by hydrophobic interactions

Corrigendum to: The TianQin project: current progress on science and technology

In the originally published version, this manuscript included an error related to indicating the corresponding author within the author list. This has now been corrected online to reflect the fact that author Jun Luo is the corresponding author of the article

Auditor Choice, Earnings Management, and Performance of Chinese Listed Family Firms:The Impact of Political Connection

Political influence in the private sector has become increasingly significant in the prevailing debate. Despite the rise of family conglomerates worldwide, the impact of political connection on family firms is still underexplored in the literature. In China, political connection is crucial for the survival and development of family firms. This work aims to fill the gap and examine how connections with various levels of government affect family firms’ accounting practices (i.e., choice of auditor and earnings management) and performance. Employing the resource dependency theory, I argue that controlling families and managers are motivated to develop political connection to access valuable economic and social assets and consequently build up comparative advantage. However, the family firms may also experience serious agency conflicts arising from both concentrated ownership structure and political connection, which have substantial implications on their choice of auditors, financial reporting quality and firm performance. Connection with government is beneficial to mitigate political and social discrimination, but simultaneously may turn those firms into the agents in pursuit of political interest. Then the incentive of the politicians is vital to shape the behaviour and performance of family firms. In fact, politicians at different hierarchical levels (i.e., central and local) have diverse priorities and objectives. The unique setup of central control and regional autonomy in the Chinese institutional environment provide a perfect context to explore the differential impacts of political connection at various levels of government on family firms. The findings show that locally connected family firms are more likely to appoint small auditors when the CEO also take the board chairman role, manage earnings through accrual-based and real activities, and have reduced performance than those connect with central government. Such effects are robust using alternative measure and models

Lifelong Person Re-identification via Knowledge Refreshing and Consolidation

Lifelong person re-identification (LReID) is in significant demand for real-world development as a large amount of ReID data is captured from diverse locations over time and cannot be accessed at once inherently. However, a key challenge for LReID is how to incrementally preserve old knowledge and gradually add new capabilities to the system. Unlike most existing LReID methods, which mainly focus on dealing with catastrophic forgetting, our focus is on a more challenging problem, which is, not only trying to reduce the forgetting on old tasks but also aiming to improve the model performance on both new and old tasks during the lifelong learning process. Inspired by the biological process of human cognition where the somatosensory neocortex and the hippocampus work together in memory consolidation, we formulated a model called Knowledge Refreshing and Consolidation (KRC) that achieves both positive forward and backward transfer. More specifically, a knowledge refreshing scheme is incorporated with the knowledge rehearsal mechanism to enable bi-directional knowledge transfer by introducing a dynamic memory model and an adaptive working model. Moreover, a knowledge consolidation scheme operating on the dual space further improves model stability over the long-term. Extensive evaluations show KRC’s superiority over the state-of-the-art LReID methods with challenging pedestrian benchmarks. Code is available at https://github.com/cly234/LReID-KRKC

Improvement in the Analytical Capabilities of LA-ICP-MS for High Spatial Resolution U-Pb Dating of Zircon Using Mixed-Gas Plasma

In this work, a novel method for high spatial resolution U-Pb dating of zircon by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) at 10–16 μm spot diameter has been proposed. This was achieved by introducing 2% (v/v) water-ethanol vapours into ICP in combination with the shielded torch system to increase the sensitivity and suppress the isotopic fractionation effect. Precise and accurate concordant U-Pb ages for Plešovice, GJ-1, and 91500 zircons were obtained using the proposed method, and the results agreed well with the isotope dilution-thermal ionization mass spectrometry (ID-TIMS) and LA-ICP-MS within 2σ, except for the ages obtained using dry plasma at 10 μm spot diameter. Additionally, the effects of plasma condition (dry plasma or 2% (v/v) ethanol plasma) and spot size (10, 16, 24, or 32 μm) on precision (RSD), accuracy (RE), and uncertainty (2σ) of the 206Pb/238U ages have been studied. The results indicated that increasing the spot diameter and introducing 2% (v/v) water-ethanol vapours into ICP significantly improved the precision, accuracy, and uncertainty for small spot diameters (10 and 16 μm), while it exhibited little influence for intermediate spot diameters (24 and 32 μm). Furthermore, the effects of spot size and plasma condition on the precision, accuracy, and uncertainty strongly depended on the sensitivity of analytes

Primary ectopic meningiomas: Report of 6 cases with emphasis on atypical morphology and exploratory immunohistochemistry

Aims. To investigate the histological and immunohistochemical features of primary ectopic meningiomas (PEMs), especially those of primary ectopic atypical meningiomas (PEAMs). Methods and results. We examined 6 cases of PEM, including 2 PEAM cases, which occurred separately in left nasal cavity, left lower lung, right neck, left orbit, right upper lung, and left upper lung by histological and immunohistochemical analysis. In general, of the 6 PEM cases analyzed, 4 cases exhibited morphology of Grade I, including 1 fibrous, 1 meningothelial, and 2 transitional variant. The remaining 2 cases shared similar atypical morphology of Grade II. The tumors were distributed in sheet-like patterns with loss of architecture of classic meningiomas. Significant hypercellularity, multi-focal necrosis, and thin-walled blood vessels were identified. The mitotic figures were estimated at 6 per 10 high-power fields in one case, and 8 mitotic figures in another. Immunohistochemically, the 6 PEM cases were all positive for Vimentin and EMA, while none showed immunostaining for CKpan, S-100, CD34, STAT6, SMA, Syn or Bcl-2. 4 PEM cases of Grade I were immunoreactive for PR but negative for P53, while the 2 PEAM cases displayed negative staining for PR but positivity for P53. As for Ki-67, the positive staining of 4 Grade I cases was no greater than 2%, while the positive rates of the 2 PEAM cases were 10% and 20%. Conclusions. Our study has expanded cases of PEMs, especially the 2 PEAM cases in rare sites. Our study has also further summarized the pathological features of PEMs, focusing on the histological features of PEAMs, and the immunohistochemical features worthy of further investigation

Legume/Maize Intercropping and N Application for Improved Yield, Quality, Water and N Utilization for Forage Production

Legume/maize intercropping has been practiced in many countries as a sustainable cropping system, but the effects of intercropping legumes with maize together with N application rates on biomass yield, quality, water-use efficiency (WUE), and nitrogen use efficiency (NUE) are limited under arid conditions in Northwest China. Field experiments were carried out in arid areas of Northwest China from 2019 to 2020 with three planting patterns (LM: Dolichos lablab (Lablab purpureus L.)/silage maize (Zea mays L.) intercropping; FM: Fodder soybean (Glycine max L.)/silage maize intercropping; M: silage maize monoculture) and four N application levels (N1: 0 kg N ha−1; N2: 120 kg N ha−1; N3: 240 N kg ha−1; N4: 360 N kg ha−1). The results showed that nitrogen fertilizer had a significant (p < 0.01) effect on total yield, WUE, and various nutrient parameters and the interaction between planting mode and nitrogen fertilizer had no significant effect on the above indicators, but had a significant (p < 0.01) effect on NUE. Compared with N1, the N3 and N4 treatments significantly increased fresh and hay yield, crude protein yield, crude protein concentration, and crude fat concentration of maize, legumes, and the whole silage system, and decreased the concentration of neutral detergent fiber (NDF) and acid detergent fiber (ADF). In comparison with N1, the 2-year average total biomass yield of N3 and N4 increased by 60.38% and 56.45%, respectively, and the total crude protein yield increased by 106.71% and 100.00%, respectively. High N input treatments (N3 and N4) significantly increased WUEB (the WUE of legume and maize biomass), N concentration, N uptake, and NUE than N1, and the 2-year average NUE of N3 was 59.52% greater than that of N4. The results also show that LM and FM increased crude protein concentration and decreased NDF and ADF concentration compared with M, and the forage quality of LM was greater than that of FM. In contrast with M, LM and FM increased biomass yield by 3.70% and 1.72%, crude protein yield by 32.05% and 22.82%, and WUEB by 10.49% and 6.02%, respectively. Application of 240 kg N ha−1 in the Dolichos lablab–maize intercropping systems produced better dry biomass yield with increased forage qualities than other treatments, but the economic analysis is needed before making a recommendation