Analysts are weighing in today on chemicals producer Celanese Corporation (CE - 48.46), medical supply company Hologic, Inc. (HOLX - 19.12), and Texas Instruments Incorporated (TXN - 31.94). Here's a quick roundup of today's bearish brokerage notes.

• CLSA slashed its rating on CE to "underperform" from "outperform," representing a rare negative note for the stock. Heading into today's trading, CE had garnered nine "buy" or better ratings from analysts, three middling "holds," and zero "sells." The shares have added a respectable 9.5% so far in 2012, but they're currently trading just below emerging resistance in the $48.50-$50 area. The stock hasn't closed a session above this region since late February.
• After making some M&A waves on Monday, HOLX today was cut to "neutral" from "outperform" at Macquarie. The shares tumbled to a loss of nearly 10% yesterday following news of an all-cash, $3.7-billion bid to buy Gen-Probe (GPRO), with HOLX giving up support at the $20 level in the process. Going forward, this round-number level could switch roles to act as resistance -- as could the stock's formerly supportive 80-day moving average, which is currently perched just north of $20.50.
• As part of a broader note on semiconductor stocks, Macquarie lowered its opinion of TXN to "neutral" from "outperform," and trimmed its price target to $33.20 from $35.70. The stock is set to open the day fractionally lower, deepening its 52-week decline of 8.8%. TXN is in the process of pulling back from pressure in the $34 area. This key chart level served as support during the first half of 2011, but has consistently thwarted all of TXN's rally attempts in 2012.