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Signed difference sets have interesting applications in communications and coding theory. A (v , k , λ) -difference set in a finite group G of order v is a subset D of G with k distinct elements such that the expressions x y - 1 for all distinct two elements x , y ∈ D , represent each non-identity element in G exactly λ times. A (v , k , λ) -signed difference set is a generalization of a (v , k , λ) -difference set D, which satisfies all properties of D, but has a sign for each element in D. We will show some new existence results for signed difference sets by using partial difference sets, product methods, and cyclotomic classes. [ABSTRACT FROM AUTHOR]

Enhanced recovery after surgery (ERAS) pathway comprises a set of comprehensive elements which have been reported to enhance patient postoperative prognosis. In the current study, we aimed to evaluate the effectiveness of the ERAS in patients undergoing laparoscopic adrenal resection. A retrospective review was performed to compare the outcomes of patients undergoing adrenalectomy for primary aldosteronism between the pre-ERAS period and the ERAS era. Data was generated from the traditional surgical period (September 1, 2019, to December 31, 2019) and the ERAS period (September 1, 2020, to December 31, 2020), respectively. Forty-seven adrenalectomy patients were enrolled (pre-ERAS, n = 21; ERAS, n = 26) in analysis. The results revealed that both total length of hospital stay and postoperative length of stay decreased in the ERAS period compared with the pre-ERAS period (14.19 ± 4.96 vs 11.27 ± 4.37, p = 0.015; 5.43 ± 1.08 vs 3.31 ± 0.97, p < 0.001). The medical expenses decreased significantly in the ERAS group (p < 0.05). While, the surgery-related complications, including urinary retention, retroperitoneal effusion and gastrointestinal discomfort, possessed no statistical difference. The ERAS pathway was safe and feasible for adrenalectomy in patients with primary aldosteronism. The ERAS could promote patients to quickly recover from the postoperative status to a physiological state, and decrease the length of hospitalization and medical cost after surgery. [ABSTRACT FROM AUTHOR]

Locking of longitudinal modes in laser cavities is the common path to generate ultrashort pulses. In traditional multi-wavelength mode-locked lasers, the group velocities rely on lasing wavelengths due to the chromatic dispersion, yielding multiple trains of independently evolved pulses. Here, we show that mode-locked solitons at different wavelengths can be synchronized inside the cavity by engineering the intracavity group delay with a programmable pulse shaper. Frequency-resolved measurements fully retrieve the fine temporal structure of pulses, validating the direct generation of synchronized ultrafast lasers from two to five wavelengths with sub-pulse repetition-rate up to ~1.26 THz. Simulation results well reproduce and interpret the key experimental phenomena, and indicate that the saturable absorption effect automatically synchronize multi-wavelength solitons in despite of the small residual group delay difference. These results demonstrate an effective approach to create synchronized complex-structure solitons, and offer an effective platform to study the evolution dynamics of nonlinear wavepackets. The coherence degradation of pulses synchronized to optical cavities is an issue for ultrahigh-repetition-rate lasing. Here the authors demonstrate synchronized multi-wavelength mode-locked soliton fiber lasers generating ultrafast outputs from two to five wavelengths with a high sub-pulse repetition rate. [ABSTRACT FROM AUTHOR]

This paper is devoted to the affine-invariant ternary codes defined by Hermitian functions. We first compute the incidence matrices of the 2-designs supported by the minimum weight codewords of these ternary codes. Then we show that the linear codes spanned by the rows of these incidence matrices are subcodes of the 4-th order generalized Reed-Muller codes and also hold 2-designs. Finally, we determine the dimension and develop a lower bound on the minimum distance of the ternary linear codes. [ABSTRACT FROM AUTHOR]

In this paper, we construct directed strongly regular graphs with new parameters by using partial sum families with local rings. 16 families of new directed strongly regular graphs are obtained and the uniform partial sum families are given. Based on the cyclotomic numbers of finite fields, we present two infinite families of directed strongly regular Cayley graphs from semi-direct products of groups. [ABSTRACT FROM AUTHOR]