Uncovering the Molecular Composition and Architecture of the Bacillus subtilis Biofilm via Solid-State NMR Spectroscopy

The complex and dynamic compositions of biofilms, along with their sophisticated structural assembly mechanisms, endow them with exceptional capabilities to thrive in diverse conditions that are typically unfavorable for individual cells. Characterizing biofilms in their native state is significantly challenging due to their intrinsic complexities and the limited availability of noninvasive techniques. Here, we utilized solid-state nuclear magnetic resonance (NMR) spectroscopy to analyze Bacillus subtilis biofilms in-depth. Our data uncover a dynamically distinct organization within the biofilm: a dominant, hydrophilic, and mobile framework interspersed with minor, rigid cores of limited water accessibility. In these heterogeneous rigid cores, the major components are largely self-assembled. TasA fibers, the most robust elements, further provide a degree of mechanical support for the cell aggregates and some lipid vesicles. Notably, rigid cell aggregates can persist even without the major extracellular polymeric substance (EPS) polymers, although this leads to slight variations in their rigidity and water accessibility. Exopolysaccharides are exclusively present in the mobile domain, playing a pivotal role in its water retention property. Specifically, all water molecules are tightly bound within the biofilm matrix. These findings reveal a dual-layered defensive strategy within the biofilm: a diffusion barrier through limited water mobility in the mobile phase and a physical barrier posed by limited water accessibility in the rigid phase. Complementing these discoveries, our comprehensive, in situ compositional analysis is not only essential for delineating the sophisticated biofilm architecture but also reveals the presence of alternative genetic mechanisms for synthesizing exopolysaccharides beyond the known pathway

Estimated SNR.

<p>Estimated SNR.</p

F28, poorly differentiated squamous cell carcinoma (stage II B) with negative cystoscopic findings.

<p>Pathology of intraoperative biopsy found cancer cells between the anterior wall of the cervix and bladder. Directly acquired contrast-enhanced sagittal image (A) shows a large cervical cancer lesion with relative lower signal compared with the surrounding cervical stroma. The anterior cervical stroma is suspicious interrupted (arrow). Sagittal image reconstructed by isotropic sequence (B) and axial isotropic image (C) clearly demonstrate that the anterior cervical stroma is interrupted by tumor (arrowhead). An OB tampons was placed inside the vagina (star).</p

F47, poorly differentiated squamous cell carcinoma of the cervix (stage II A2) invades the vaginal fornix and cervical canal mucosa.

<p>Directly acquired contrast-enhanced sagittal image (A) shows a tumor in the anterior cervical lip with relative lower signal compared with the surrounding cervical stroma. Oblique sagittal image (B) and coronal CPR image (C), which were both reconstructed by the Isotropy, show more clearly that the lesion has spread to the cervical canal and vaginal fornix (arrow).</p

Box and whisker plots of estimated SNR of myometrium.

<p>The estimated SNRs of the myometrium in reconstructed images are higher than those in directly acquired images of both sagittal and coronal plane (<i>p</i> = 0.001 and 0.002, respectively).</p

Box and whisker plots of relative tumor contrast.

<p>The relative tumor contrast between tumor to gluteal muscle and between tumor to fat in the directly acquired were higher than those in the reconstructed images (<i>p</i> = 0.001 and 0.031, sagittal; both <i>p</i> < 0.001, coronal). While the relative tumor contrast between tumor to myometrium was not statistically different for directly acquired and reconstructed either on sagittal or coronal images (<i>p</i> = 0.642 and 0.171, respectively).</p

Ultrathin Stretchable Triboelectric Nanogenerators Improved by Postcharging Electrode Material

Sustainable ultrathin stretchable power sources have emerged with the development of wearable electronics. They obtain energy from living organisms and the environment to drive these wearable electronics. Here, an ultrathin stretchable and triboelectric nanogenerator (TENG) improved by chargeable carbon black (CB)/thermoplastic polyurethane (TPU) composite material (CT-TENG) is proposed for mechanical energy harvesting and physiological signal sensing. The CB/TPU composite can act as both a stretchable electrode and a triboelectric layer due to the coexistence of conductive CB and dielectric TPU. The CT-TENG demonstrates good stretchability (≈646%), ultrathin thickness (≈50 μm), and a lightweight (≈62 mg). The triboelectric electrode material can be improved by postcharging treatment. With the corona charging process, the output performance of the CT-TENG was improved eightfold and reached 41 V. Moreover, the CT-TENG with a self-powered sensing capability can inspect the amplitude and frequency of different physiological movements. Consequently, the CT-TENG is promising in promoting the development of electronic skins, wearable systems of self-powered sensors, human–machine interactions, soft robotics, and artificial intelligence applications

Relative tumor contrast between tumor to gluteal muscle.

<p>Relative tumor contrast between tumor to gluteal muscle.</p

F55, poorly differentiated squamous cell carcinoma (stage IIA1).

<p>Directly acquired contrast-enhanced sagittal image (A) shows a tumor in the posterior cervical lip invading the vaginal fornix (arrow), with relative lower signal compared with the surrounding cervical stroma. Directly acquired contrast-enhanced coronal image (B) fails to show the entire uterus and the relationship between the lesion and vagina due to uterine anteversion. CPR from isotropic sequence (C) reconstructs the uterine and vaginal lesions in the same slice so that the relationship between the lesion and the vagina is more clearly displayed (arrow).</p

Parameters of contrast-enhanced sagittal, axial isotropic and coronal scans.

<p>Note: Scan slices varied according to patient’s body size, therefore, the scan time for each patient may have also varied. Sagittal and coronal scans covered the entire pelvic cavity and the axial scan covered the entire uterus and vagina.</p><p>Parameters of contrast-enhanced sagittal, axial isotropic and coronal scans.</p