Identification of motor and sensory nerves is important in applications such as nerve injury repair. Conventional practice relies on time consuming staining methods for this purpose. Here, we use laser scanning infrared differential interference contrast (IR-DIC) microscopy for label-free observation of the two types of nerve. Ventral and dorsal nerve roots of adult beagle dogs were collected and sections of different thicknesses were imaged with an IR-DIC microscope. Different texture patterns of the IR-DIC images of the motor and sensory nerve can be distinguished when the section thickness increases to 40 μm. This suggests that nerve fibers in motor and sensory nerves have different distribution patterns. The result hints a potential new way for more rapid identification of nerve type in peripheral nerve repair surgery.

This study aimed to investigate the influence of laparoscopic total mesorectal excision combined with sphincter-preserving surgery on the postoperative defecation function, urinary function and sexual function in low or ultralow rectal cancer. A retrospective study was undertaken on 107 patients (65 laparoscopic resection and 42 laparoctomic resection) with rectal cancer undergoing laparoscopic or open laparoscopic total mesorectal excision combined with sphincter-preserving surgery from April 2009 to April 2013. The quality of life outcomes of all patients, including defection, urinary and sexual function, were assessed at 6, 12 and 24 months after operation. Gastrointestinal quality of life index (GQOLI) was used to evaluate the fecal incontinence and bowel dysfunction. Urinary and sexual functions were studied by means of questionnaires on the basis of the international prostatic symptom score (IPSS) and international index of erectile function (IIEF), respectively. In laparoscopic surgery group, there were two cases of anastomotic leakage, three cases of anastomotic stricture, seven cases of local recurrence, ten cases of hepatic metastasis and five cases of lung metastasis. The satisfaction rates of patients about their defecation function reached 60.3% (35/58, 84.5% (49/58) and 91.3% (53/58) at 6, 12, and 24 months follow-up, respectively. The assessment after one year showed that the overall incidence of urinary dysfunction was 10.7% (7/65); Among male patients, 18.4% (7/36) suffered from erectile dysfunction and 27.8% (10/36) suffered from ejaculatory dysfunction; 65.5% (19/29) female patients investigated were satisfied with their postoperative sexual life. In open surgery group, there were two cases of anastomotic leakage, two cases of anastomotic stricture, nine cases of local recurrence, ten cases of hepatic metastasis and seven cases of lung metastasis. The satisfaction rates of patients about their defecation function were 56.4% (22/39), 82.1% (32/39) and 94.8% (37/39) at 6, 12, and 24 months follow-up, respectively. The assessment after one year showed that the overall incidence of urinary dysfunction was 11.9% (5/42); 25% (4/16) male patients suffered from erectile dysfunction and 31.3% (5/16) suffered from ejaculatory dysfunction; 69.2% (19/26) female patients investigated were satisfied of their postoperative sexual life. There was no statistic difference in the two groups. Laparoscopic total mesorectal excision combined with sphincter-preserving surgery in low or ultralow rectal carcinoma is safe and practicable. It can be helpful for enhancing the probability of anus reservation, and obtains satisfactory defecation, sexual and urinary functions.

In this paper, we consider a method of laser resection using the silica glass core from which the cladding layer has been removed as the cutting part of a laser scalpel. An absorbing layer coating the silica fiber tip markedly alters its biotissue cutting characteristics. The results of histological studies of skin after exposure to a laser scalpel with and without a strongly absorbing coating (SAC) at a wavelength of 0.97 μm show that resection using a coated scalpel is more sparing. When an uncoated scalpel was used, skin injury was more apparent in both its surface spread and the depth of structural damage, resulting in poorer tissue regeneration.

We demonstrate the possibility of detection and monitoring of bubbles emerging near the tip of an optical fiber by means of ultrasonic method. The excitation of bubbles at their resonant frequencies is performed using short ultrasonic pulses having a wide frequency range simultaneously with their modulation by means of a long pulse of a monochromatic frequency. This method allows detection of bubbles of various sizes. Used signal processing method, which allows increased bubble detection accuracy, is proposed for research in environments of biological-like medium which show continuous variations in structure and properties when exposed to optical emission. The method has been demonstrated on model objects: in a liquid and in a biological tissue phantom using various methods of bubble generation (hydrolysis and optical emission). We studied bubble formation by the tip of a fiber of the surgical laser LSP-007/10 “IRE Polus" with a wavelength of 0.97 μm coated with a highly absorbing graphite layer.

The incidence of nonmelanoma skin cancer is rising worldwide. The major carcinogenic factor for most skin cancers is solar ultraviolet light, in particular, the chronic exposure to UVB (280–320 nm). In this study, the optical characteristics of skin canceration process induced by UVB were analyzed. Optical coherence tomography (OCT) was used for monitoring the morphologic changes and compared with histological analysis. Meanwhile, the optical property, such as the attenuation coefficient (μt) was systematically extracted and analyzed. In addition, characteristic textures, including energy, entropy and correlation were revealed from OCT images. Results suggest that OCT is a useful tool for monitoring the process of UVB-induced skin cancer and changes of optical property during this process.

Here, we report a new method using combined magnetic resonance (MR)–Photoacoustic (PA)– Thermoacoustic (TA) imaging techniques, and demonstrate its unique ability for in vivo cancer detection using tumor-bearing mice. Circular scanning TA and PA imaging systems were used to recover the dielectric and optical property distributions of three colon carcinoma bearing mice While a 7.0-T magnetic resonance imaging (MRI) unit with a mouse body volume coil was utilized for high resolution structural imaging of the same mice. Three plastic tubes filled with soybean sauce were used as fiducial markers for the co-registration of MR, PA and TA images. The resulting fused images provided both enhanced tumor margin and contrast relative to the surrounding normal tissues. In particular, some finger-like protrusions extending into the surrounding tissues were revealed in the MR/TA infused images. These results show that the tissue functional optical and dielectric properties provided by PA and TA images along with the anatomical structure by MRI in one picture make accurate tumor identification easier. This combined MR–PA–TA-imaging strategy has the potential to offer a clinically useful triplemodality tool for accurate cancer detection and for intraoperative surgical navigation.

Blood cell counting is an important medical test to help medical staffs diagnose various symptoms and diseases. An automatic segmentation of complex overlapping erythrocytes based on seed prediction in microscopic imaging is proposed. The four main innovations of this research are as follows: (1) Regions of erythrocytes extracted rapidly and accurately based on the G component. (2) K-means algorithm is applied on edge detection of overlapping erythrocytes. (3) Traces of erythrocytes' biconcave shape are utilized to predict erythrocyte's position in overlapping clusters. (4) A new automatic counting method which aims at complex overlapping erythrocytes is presented. The experimental results show that the proposed method is efficient and accurate with very little running time. The average accuracy of the proposed method reaches 97.0%.

Oral cancers suffer from poor disease-free survival rates due to delayed diagnosis. Noninvasive, rapid, objective approaches as adjuncts to visual inspection can help in better management of oral cancers. Raman spectroscopy (RS) has shown potential in identification of oral premalignant and malignant conditions and also in the detection of early cancer changes like cancer-field-effects (CFE) at buccal mucosa subsite. Anatomic differences between different oral subsites have also been reported using RS. In this study, anatomical differences between subsites and their possible influence on healthy vs pathological classification were evaluated on 85 oral cancer and 72 healthy subjects. Spectra were acquired from buccal mucosa, lip and tongue in healthy, contralateral (internal healthy control), premalignant and cancer conditions using fiber-optic Raman spectrometer. Mean spectra indicate predominance of lipids in healthy buccal mucosa, contribution of both lipids and proteins in lip while major dominance of protein in tongue spectra. From healthy to tumor, changes in protein secondary-structure, DNA and heme-related features were observed. Principal component linear discriminant analysis (PC-LDA) followed by leave-one-out-crossvalidation (LOOCV) was used for data analysis. Findings indicate buccal mucosa and tongue are distinct entities, while lip misclassifies with both these subsites. Additionally, the diagnostic algorithm for individual subsites gave improved classification efficiencies with respect to the pooled subsites model. However, as the pooled subsites model yielded 98% specificity and 100% sensitivity, this model may be more useful for preliminary screening applications. Large-scale validation studies are a pre-requisite before envisaging future clinical applications.

Contamination by accidental cutaneous contact with the commercial products and the air pollutants raised a considerable health and safety issue. This study aimed to trace the dynamics of the 20 nm gold nanoparticle (GNP) penetration and accumulation in rat skin tissues using a surface-enhanced Raman scattering (SERS) technique. After the topical application of GNPs on rat skin surface, the SERS spectra were recorded for every 15 μm to an overall depth of 75 μm from skin surface for 150 min. The processes of GNP penetration in rat skin were accompanied by aggregation of GNPs, which affected SERS spectra. The results revealed that 20 nm GNPs can penetrate through stratum corneum layer, viable epidermis layer, and then into dermis layer. This study demonstrated for the first time the potential of SERS spectroscopy to monitor the penetration and accumulation of GNPs in rat skin.

Optical immersion clearing is a technique that has been widely studied for more than two decades and that is used to originate a temporary transparency effect in biological tissues. If applied in cooperation with clinical methods it provides optimization of diagnosis and treatment procedures. This technique turns biological tissues more transparent through two main mechanisms — tissue dehydration and refractive index (RI) matching between tissue components. Such matching is obtained by partial replacement of interstitial water by a biocompatible agent that presents higher RI and it can be completely reversible by natural rehydration in vivo or by assisted rehydration in ex vivo tissues. Experimental data to characterize and discriminate between the two mechanisms and to find new ones are necessary. Using a simple method, based on collimated transmittance and thickness measurements made from muscle samples under treatment, we have estimated the diffusion properties of glucose, ethylene glycol (EG) and water that were used to perform such characterization and discrimination. Comparing these properties with data from literature that characterize their diffusion in water we have observed that muscle cell membrane permeability limits agent and water diffusion in the muscle. The same experimental data has allowed to calculate the optical clearing (OC) efficiency and make an interpretation of the internal changes that occurred in muscle during the treatments. The same methodology can now be used to perform similar studies with other agents and in other tissues in order to solve engineering problems at design of inexpensive and robust technologies for a considerable improvement of optical tomographic techniques with better contrast and in-depth imaging.

For many tiller crops, the plant architecture (PA), including the plant fresh weight, plant height, number of tillers, tiller angle and stem diameter, significantly affects the grain yield. In this study, we propose a method based on volumetric reconstruction for high-throughput three-dimensional (3D) wheat PA studies. The proposed methodology involves plant volumetric reconstruction from multiple images, plant model processing and phenotypic parameter estimation and analysis. This study was performed on 80 Triticum aestivum plants, and the results were analyzed. Comparing the automated measurements with manual measurements, the mean absolute percentage error (MAPE) in the plant height and the plant fresh weight was 2.71% (1.08 cm with an average plant height of 40.07 cm) and 10.06% (1.41 g with an average plant fresh weight of 14.06 g), respectively. The root mean square error (RMSE) was 1.37 cm and 1.79 g for the plant height and plant fresh weight, respectively. The correlation coefficients were 0.95 and 0.96 for the plant height and plant fresh weight, respectively. Additionally, the proposed methodology, including plant reconstruction, model processing and trait extraction, required only approximately 20 s on average per plant using parallel computing on a graphics processing unit (GPU), demonstrating that the methodology would be valuable for a high-throughput phenotyping platform.

High resolution optical endoscopes are increasingly used in diagnosis of various medical conditions of internal organs, such as the cervix and gastrointestinal (GI) tracts, but they are too expensive for use in resource-poor settings. On the other hand, smartphones with high resolution cameras and Internet access have become more affordable, enabling them to diffuse into most rural areas and developing countries in the past decade. In this paper, we describe a smartphone microendoscope that can take fluorescence images with a spatial resolution of 3.1 μm. Images collected from ex vivo, in vitro and in vivo samples using the device are also presented. The compact and cost-effective smartphone microendoscope may be envisaged as a powerful tool for detecting pre-cancerous lesions of internal organs in low and middle-income countries (LMICs).