Recent advances in protein backbone generation have achieved promising results under structural, functional, or physical constraints. However, existing methods lack the flexibility for precise topology control, limiting navigation of the backbone space. We present $\textbf{ProtPainter}$, a diffusion-based approach for generating protein backbones conditioned on 3D curves. ProtPainter follows a two-stage process: curve-based sketching and sketch-guided backbone generation. For the first stage, we propose $\textbf{CurveEncoder}$, which predicts secondary structure annotations from a curve to parametrize sketch generation. For the second stage, the sketch guides the generative process in Denoising Diffusion Probabilistic Modeling (DDPM) to generate backbones. During the process, we further introduce a fusion scheduling scheme, Helix-Gating, to control the scaling factors. To evaluate, we propose the first benchmark for topology-conditioned protein generation, introducing Protein Restoration Task and a new metric, self-consistency Topology Fitness (scTF). Experiments demonstrate ProtPainter's ability to generate topology-fit (scTF $>$ 0.8) and designable (scTM $>$ 0.5) backbones, with drawing and dragging tasks showcasing its flexibility and versatility.

Wireless body area networks (WBANs) collect some physiological parameters of the human body. Each sensor uses limited energy to maximize its own life. There are three crucial problems including adaptiveness, energy, and security in WBANs. In order to solve these problems, a flexible and secure data transmission system is proposed in this paper. The proposed scheme is composed of semitensor compressive sensing (CS), hash function, Arnold scrambling, and chaotic scrambling. For the adaptiveness problem, our scheme uses semitensor CS to encrypt multiple signals with different dimensions. The chaotic sequence is applied to generate the semitensor measurement matrix. On the one hand, we only transmit a few chaotic parameters, which reduces the number of data storage and transmission. On the other hand, the size of the measurement matrix is small, and the computation overhead can be reduced. The security is considered by the proposed scheme which combines Arnold scrambling and logistic scrambling to improve the encryption effect. Numerical simulations and security analyses are given to show that our scheme performs well. The total key space is approximately 2420. The absolute value of adjacent pixel correlation is less than 0.004. Traditional CS method stores 524 288 bytes, while the proposed scheme only stores 2048 bytes. When the compression ratio is less than 0.7, the peak signal to noise ratio of our scheme is obviously higher than those of other three schemes.