Investigating a Boronate-Affinity-Guided Acylation Reaction for Labelling Native Antibodies

The excellent molecular recognition capabilities of monoclonal antibodies (mAbs) have opened up exciting opportunities for biotherapeutic discovery. Taking advantage of the full potential of this tool necessitates affinity ligands capable of conjugating directly with small molecules to a defined degree of biorthogonality, especially when modifying natural Abs. Herein, a bioorthogonal boronate-affinity-based Ab ligand featuring a 4-(dimethylamino)pyridine and an S-aryl thioester to label full-length Abs is reported. The photoactivatable linker in the acyl donor facilitated purification of azide-labelled Ab (N₃-Ab) was quantitatively cleaved upon brief exposure to UV light while retaining the original Ab activity. Click reactions enabled the precise addition of biotin, a fluorophore, and a pharmacological agent to the purified N₃-Abs. The resulting immunoconjugate showed selectivity against targeted cells. Bioorthogonal traceless design and reagentless purification allow this strategy to be a powerful tool to engineer native antibodies amenable to therapeutic intervention.     

Effect of growth pressure on the morphology evolution and doping characteristics in nonpolar a-plane GaN

Nonpolar a-plane GaN layers grown on r-plane sapphire substrates were examined by using a two-step growth process. The higher initial growth pressure for the nucleation layer resulted in the improved crystalline quality with lower density of both threading dislocations and basal stacking faults. This was attributed to the higher degree of initial roughening and recovery time via a growth mode transition from three-dimensional (3D) to quasi two-dimensional (2D) lateral growth. Using Hall-effect measurements, the overgrown Si doped GaN layers grown with higher initial growth pressure were found to have higher mobility. The scattering mechanism due to the dislocations was dominant especially at low temperature (<200 K) for the lower initial growth pressure, which was insignificant for the higher initial growth pressure. The temperature-dependent Hall-effect measurements for the Mg doped GaN with a higher initial growth pressure yielded the activation energy and the acceptor concentration to be 128 meV and 1.2 × 10¹⁹ cm⁻³, respectively, corresponding to about 3.6% of activation at room temperature. Two-step growth scheme with a higher initial growth pressure is suggested as a potential method to improve the performance of nonpolar a-plane GaN based devices.     

Modular design and implementation of field-programmable-gate-array-based Gaussian noise generator

The modular design of a Gaussian noise generator (GNG) based on field-programmable gate array (FPGA) technology was studied. A new range reduction architecture was included in a series of elementary function evaluation modules and was integrated into the GNG system. The approximation and quantisation errors for the square root module with a first polynomial approximation were high; therefore, we used the central limit theorem (CLT) to improve the noise quality. This resulted in an output rate of one sample per clock cycle. We subsequently applied Newton's method for the square root module, thus eliminating the need for the use of the CLT because applying the CLT resulted in an output rate of two samples per clock cycle (>200 million samples per second). Two statistical tests confirmed that our GNG is of high quality. Furthermore, the range reduction, which is used to solve a limited interval of the function approximation algorithms of the System Generator platform using Xilinx FPGAs, appeared to have a higher numerical accuracy, was operated at >350 MHz, and can be suitably applied for any function evaluation.     

The uniform laws of large numbers for the tent map

The tent map is an ergodic map defined on the unit interval. This paper considers the asymptotic behaviors of the various processes generated by the tent map. We get the uniform versions of law of large numbers for the tent map. An application to Monte Carlo integration is provided.     

Cryptanalysis and improvement of controlled secure direct communication

This paper points out that, due to a flaw in the sender＇s encoding, the receiver in Gao et al.＇s controlled quantum secret direct communication （CQSDC） protocol [Chin. Phys. 14 （2005）, No. 5, p. 893] can reveal the whole secret message without permission from the controller. An improvement is proposed to avoid this flaw.     

Experimental study on the performance of miniature heat pipes withwoven-wire wick

The thermal density of electronic system has been increased continuously because high speed and high density are required for them. The heat dissipation of CPU for a notebook PC has been recently increased to be more than 10 W, but, on the other hand, the available packaging space has been decreased. Therefore, it has become inevitable to perform cooling by using miniature heat pipes (MHPs). In the present study, a new woven-wire-type wick for the MHP is developed, which has a large capillary limit and a high productivity. These MHPs with diameters of 3 mm or 4 mm are applicable to small-sized electronic parts such as CPU of a notebook PC. Because the operational characteristics of MHPs with the diameters of 3 mm or 4 mm are different from those of general medium-size heat pipes, performance tests have been conducted in order to review heat-transfer characteristics and effects of various factors on the performance of MHPs. The design factors under consideration are fill ratio of working fluid, length of heat pipe, length of evaporator and condenser, inclination angle of installation, number of wick strand and thermal load     

Mechanism for recoverable power drift in PHEMTs

A new degradation mechanism is proposed for output power drift under rf overdrive of pseudomorphic high electron mobility transistors (PHEMT's). Similar to the previously reported power-slump mechanism, the gradual reduction in output power is caused by a decrease in the peak drain current. However, unlike power slump that is usually associated with permanent damage, in the present case the output power recovers readily once the rf input is interrupted. A possible mechanism for power drift involves charge trapping in the surface passivation layer. The passivation charge relaxes the electrical field in the semiconductor, which in turn increases the occupation of the interface states between the passivation and semiconductor. Measurements of dc and pulsed current-voltage (I-V) characteristics, rf large signal waveforms, deep level transient spectroscopy, light and temperature effects, as well as metal-insulator-metal leakage support this supposition     

High-speed digital data transmission using mid-infrared quantumcascade lasers

High-speed mid-infrared quantum cascade lasers with direct modulation bandwidth of approximately 7 GHz have been developed. Error-free digital data transmission at 2.5 Gbit/s is demonstrated with devices emitting at 8 μm and operating at temperatures up to 85 K     

The Cost Distribution of Queue-Mergesort, Optimal Mergesorts, and Power-of-2 Rules

Queue-mergesort is introduced by Golin and Sedgewick as an optimal variant of mergesorts in the worst case. In this paper, we present a complete analysis of the cost distribution of queue-mergesort, including the best, average, and variance cases. The asymptotic normality of its cost is also established under the uniform permutation model. We address the corresponding optimality problems and we show that if we fix the merging scheme then the optimal mergesort as far as the average number of comparisons is concerned is to divide as evenly as possible at each recursive stage (top-down mergesort). On the other hand, the variance of queue-mergesort reaches asymptotically the minimum value. We also characterize a class of mergesorts with the latter property. A comparative discussion is given on the probabilistic behaviors of top-down mergesort, bottom-up mergesort, and queue-mergesort. We derive an “invariance principle” for asymptotic linearity of divide-and-conquer recurrences based on general “power-of-2” rules of which the underlying dividing rule of queue-mergesort is a special case. These analyses reveal an interesting algorithmic feature for general power-of-2 rules.